U.S. SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                    FORM 10-Q

[X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
     ACT OF 1934

     For the quarterly period ended September 30, 2006

[ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF 1934

     For the transition period from __________ to __________.

                          Commission File No. 000-26719

                           MERCANTILE BANK CORPORATION
             (Exact name of registrant as specified in its charter)


                                            
            Michigan                                       38-3360865
(State or other jurisdiction of                (IRS Employer Identification No.)
 incorporation or organization)


                 310 LEONARD STREET, NW, GRAND RAPIDS, MI 49504
               (Address of principal executive offices) (Zip Code)

                                 (616) 406-3000
              (Registrant's telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

                              Yes  X    No
                                  ---      ---

Indicate by check mark whether the registrant is a large accelerated filer, an
accelerated filer, or a non-accelerated filer. See definition of accelerated
filer and large accelerated filer in Rule 12b-2 of the Exchange Act.

Large Accelerated filer       Accelerated filer  X    Non-Accelerated filer
                        ---                     ---                         ---

Indicate by check mark whether the registrant is a shell company (as defined in
Rule 12b-2 of the Exchange Act).

                              Yes       No  X
                                  ---      ---

At November 8, 2006, there were 8,019,315 shares of Common Stock outstanding.


                                       1



                           MERCANTILE BANK CORPORATION

                                      INDEX



                                                                        Page No.
                                                                        --------
                                                                     
PART I.  Financial Information

         Item 1.  Financial Statements

         Consolidated Balance Sheets -
            September 30, 2006 (Unaudited) and December 31, 2005.....       3

         Consolidated Statements of Income and Comprehensive Income -
            Three and Nine Months Ended September 30, 2006
            (Unaudited) and September 30, 2005 (Unaudited)...........       4

         Consolidated Statements of Changes in Shareholders' Equity -
            Nine Months Ended September 30, 2006 (Unaudited) and
            September 30, 2005 (Unaudited)...........................       5

         Consolidated Statements of Cash Flows -
            Three and Nine Months Ended September 30, 2006
            (Unaudited) and September 30, 2005 (Unaudited)...........       7

         Notes to Consolidated Financial Statements (Unaudited)......       9

         Item 2. Management's Discussion and Analysis of Financial
            Condition and Results of Operations......................      22

         Item 3. Quantitative and Qualitative Disclosures About
            Market Risk..............................................      31

         Item 4. Controls and Procedures.............................      33

PART II. Other Information

         Item 1. Legal Proceedings...................................      34

         Item 1A. Risk Factors.......................................      34

         Item 2. Unregistered Sales of Equity Securities and Use of
            Proceeds.................................................      34

         Item 3. Defaults upon Senior Securities.....................      34

         Item 4. Submission of Matters to a Vote of Security
            Holders..................................................      34

         Item 5. Other Information...................................      34

         Item 6. Exhibits............................................      35

         Signatures



                                        2


                         PART I - FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

                           MERCANTILE BANK CORPORATION
                           CONSOLIDATED BALANCE SHEETS



                                                                  September 30,    December 31,
                                                                      2006             2005
                                                                 --------------   --------------
                                                                   (Unaudited)
                                                                            
ASSETS
   Cash and due from banks                                       $   39,100,000   $   36,208,000
   Short-term investments                                               176,000          545,000
   Federal funds sold                                                16,000,000                0
                                                                 --------------   --------------
      Total cash and cash equivalents                                55,276,000       36,753,000
   Securities available for sale                                    125,746,000      112,961,000
   Securities held to maturity (fair value of $63,332,000 at
      September 30, 2006 and $62,850,000 at December 31, 2005)       62,097,000       60,766,000
   Federal Home Loan Bank stock                                       7,764,000        7,887,000
   Total loans and leases                                         1,710,268,000    1,561,812,000
   Allowance for loan and lease losses                              (21,938,000)     (20,527,000)
                                                                 --------------   --------------
         Total loans and leases, net                              1,688,330,000    1,541,285,000
   Premises and equipment, net                                       32,309,000       30,206,000
   Bank owned life insurance policies                                30,150,000       28,071,000
   Accrued interest receivable                                       10,438,000        8,274,000
   Other assets                                                      14,724,000       12,007,000
                                                                 --------------   --------------
      Total assets                                               $2,026,834,000   $1,838,210,000
                                                                 ==============   ==============
LIABILITIES AND SHAREHOLDERS' EQUITY
   Deposits
      Noninterest-bearing                                        $  115,269,000   $  120,828,000
      Interest-bearing                                            1,499,434,000    1,298,524,000
                                                                 --------------   --------------
         Total deposits                                           1,614,703,000    1,419,352,000
   Securities sold under agreements to repurchase                    74,111,000       72,201,000
   Federal funds purchased                                                    0        9,600,000
   Federal Home Loan Bank advances                                  115,000,000      130,000,000
   Subordinated debentures                                           32,990,000       32,990,000
   Other borrowed money                                               3,147,000        2,347,000
   Accrued expenses and other liabilities                            19,335,000       16,595,000
                                                                 --------------   --------------
         Total liabilities                                        1,859,286,000    1,683,085,000
Shareholders' equity
   Preferred stock, no par value; 1,000,000 shares
      authorized, none issued                                                 0                0
   Common stock, no par value: 20,000,000 shares authorized;
      8,018,680 shares outstanding at September 30, 2006 and
      7,590,526 shares outstanding at December 31, 2005             161,045,000      148,533,000
   Retained earnings                                                  8,230,000        8,000,000
   Accumulated other comprehensive income (loss)                     (1,727,000)      (1,408,000)
                                                                 --------------   --------------
      Total shareholders' equity                                    167,548,000      155,125,000
                                                                 --------------   --------------
         Total liabilities and shareholders' equity              $2,026,834,000   $1,838,210,000
                                                                 ==============   ==============


          See accompanying notes to consolidated financial statements.


                                        3



                           MERCANTILE BANK CORPORATION
                        CONSOLIDATED STATEMENTS OF INCOME
                            AND COMPREHENSIVE INCOME



                                            Three Months    Three Months    Nine Months     Nine Months
                                               Ended           Ended           Ended           Ended
                                           September 30,   September 30,   September 30,   September 30,
                                                2006            2005            2006            2005
                                           -------------   -------------   -------------   -------------
                                            (Unaudited)     (Unaudited)     (Unaudited)     (Unaudited)
                                                                               
Interest income
   Loans and leases, including fees         $33,261,000     $24,570,000     $ 93,292,000   $66,592,000
   Investment securities                      2,335,000       2,113,000        6,871,000     6,036,000
   Federal funds sold                            76,000          76,000          347,000       176,000
   Short-term investments                         3,000           5,000           10,000        11,000
                                            -----------     -----------     ------------   -----------
      Total interest income                  35,675,000      26,764,000      100,520,000    72,815,000
Interest expense
   Deposits                                  17,268,000      10,554,000       46,111,000    26,886,000
   Short-term borrowings                        707,000         475,000        2,028,000     1,188,000
   Federal Home Loan Bank advances            1,452,000       1,148,000        4,136,000     3,011,000
   Long-term borrowings                         701,000         515,000        1,953,000     1,395,000
                                            -----------     -----------     ------------   -----------
      Total interest expense                 20,128,000      12,692,000       54,228,000    32,480,000
                                            -----------     -----------     ------------   -----------
NET INTEREST INCOME                          15,547,000      14,072,000       46,292,000    40,335,000
Provision for loan and lease losses           1,350,000         895,000        4,075,000     2,520,000
                                            -----------     -----------     ------------   -----------
NET INTEREST INCOME AFTER PROVISION
   FOR LOAN AND LEASE LOSSES                 14,197,000      13,177,000       42,217,000    37,815,000
Noninterest income
   Services charges on accounts                 361,000         369,000        1,006,000     1,048,000
   Net gain on sales of commercial loans              0          56,000           29,000        84,000
   Other income                               1,001,000         905,000        2,845,000     2,626,000
                                            -----------     -----------     ------------   -----------
      Total noninterest income                1,362,000       1,330,000        3,880,000     3,758,000
Noninterest expense
   Salaries and benefits                      4,731,000       4,983,000       14,179,000    13,547,000
   Occupancy                                    802,000         805,000        2,404,000     1,889,000
   Furniture and equipment                      513,000         459,000        1,550,000     1,109,000
   Other expense                              1,982,000       2,073,000        5,932,000     5,770,000
                                            -----------     -----------     ------------   -----------
      Total noninterest expenses              8,028,000       8,320,000       24,065,000    22,315,000
                                            -----------     -----------     ------------   -----------
INCOME BEFORE FEDERAL INCOME
   TAX EXPENSE                                7,531,000       6,187,000       22,032,000    19,258,000
Federal income tax expense                    2,329,000       1,887,000        6,790,000     5,906,000
                                            -----------     -----------     ------------   -----------
NET INCOME                                  $ 5,202,000     $ 4,300,000     $ 15,242,000   $13,352,000
                                            ===========     ===========     ============   ===========
COMPREHENSIVE INCOME                        $ 6,757,000     $ 3,855,000     $ 14,923,000   $12,781,000
                                            ===========     ===========     ============   ===========
Basic earnings per share                    $      0.65     $      0.54     $       1.91   $      1.68
                                            ===========     ===========     ============   ===========
Diluted earnings per share                  $      0.64     $      0.53     $       1.88   $      1.64
                                            ===========     ===========     ============   ===========
Cash dividends per share                    $      0.13     $      0.11     $       0.38   $      0.32
                                            ===========     ===========     ============   ===========
Average basic shares outstanding              8,016,016       7,965,172        7,997,187     7,956,205
                                            ===========     ===========     ============   ===========
Average diluted shares outstanding            8,118,206       8,115,575        8,117,709     8,134,657
                                            ===========     ===========     ============   ===========


          See accompanying notes to consolidated financial statements.


                                        4



                           MERCANTILE BANK CORPORATION
                           CONSOLIDATED STATEMENTS OF
                         CHANGES IN SHAREHOLDERS' EQUITY
                                   (Unaudited)



                                                                              Accumulated
                                                                                 Other           Total
                                                  Common        Retained     Comprehensive   Shareholders'
                                                   Stock        Earnings     Income/(loss)       Equity
                                               ------------   ------------   -------------   -------------
                                                                                 
BALANCE, JANUARY 1, 2005                       $131,010,000   $ 10,475,000     $ 132,000     $141,617,000
Payment of 5% stock dividend, 377,527 shares     17,187,000    (17,191,000)                        (4,000)
Employee stock purchase plan, 1,762 shares           69,000                                        69,000
Dividend reinvestment plan, 3,477 shares            136,000                                       136,000
Stock option exercises, 39,446 shares               368,000                                       368,000
Stock tendered for stock option exercises,
   7,565 shares                                    (298,000)                                     (298,000)
Cash dividends, $0.32 per share                                 (2,349,000)                    (2,349,000)
Comprehensive income:
   Net income for the period from January 1,
      2005 through September 30, 2005                           13,352,000                     13,352,000
   Change in net unrealized gain/(loss)
      on securities available for sale, net
      of reclassifications and tax effect                                       (571,000)        (571,000)
                                                                                             ------------
         Total comprehensive income                                                            12,781,000
                                               ------------   ------------     ---------     ------------
BALANCE, SEPTEMBER 30, 2005                    $148,472,000   $  4,287,000     $(439,000)    $152,320,000
                                               ============   ============     =========     ============


          See accompanying notes to consolidated financial statements.


                                        5


                           MERCANTILE BANK CORPORATION
                           CONSOLIDATED STATEMENTS OF
                   CHANGES IN SHAREHOLDERS' EQUITY (Continued)
                                   (Unaudited)



                                                                              Accumulated
                                                                                 Other           Total
                                                  Common        Retained     Comprehensive   Shareholders'
                                                   Stock        Earnings     Income/(loss)       Equity
                                               ------------   ------------   -------------   -------------
                                                                                 
BALANCE, JANUARY 1, 2006                       $148,533,000   $  8,000,000    $(1,408,000)   $155,125,000
Payment of 5% stock dividend, 379,432 shares     12,014,000    (12,018,000)                        (4,000)
Employee stock purchase plan, 2,144 shares           83,000                                        83,000
Dividend reinvestment plan, 1,970 shares             76,000                                        76,000
Stock option exercises, 59,126 shares               755,000                                       755,000
Stock tendered for stock option exercises,
   14,518 shares                                   (569,000)                                     (569,000)
Stock option expense                                153,000                                       153,000
Cash dividends, $0.38 per share                                 (2,994,000)                    (2,994,000)
Comprehensive income:
   Net income for the period from January 1,
      2006 through September 30, 2006                           15,242,000                     15,242,000
   Change in net unrealized gain/(loss)
      on securities available for sale, net
      of reclassifications and tax effect                                        (319,000)       (319,000)
                                                                                             ------------
      Total comprehensive income                                                               14,923,000
                                               ------------   ------------    -----------    ------------
BALANCE, SEPTEMBER 30, 2006                    $161,045,000   $  8,230,000    $(1,727,000)   $167,548,000
                                               ============   ============    ===========    ============


          See accompanying notes to consolidated financial statements.


                                        6



                           MERCANTILE BANK CORPORATION
                      CONSOLIDATED STATEMENTS OF CASH FLOWS



                                            Three Months    Three Months    Nine Months     Nine Months
                                               Ended           Ended           Ended           Ended
                                           September 30,   September 30,   September 30,   September 30,
                                                2006            2005            2006            2005
                                           -------------   -------------   -------------   -------------
                                            (Unaudited)     (Unaudited)     (Unaudited)     (Unaudited)
                                                                               
CASH FLOWS FROM OPERATING ACTIVITIES
   Net income                              $  5,202,000    $  4,300,000    $  15,242,000   $  13,352,000
   Adjustments to reconcile net income
      to net cash from operating
      activities
      Depreciation and amortization             781,000         728,000        2,360,000       1,802,000
      Provision for loan and lease
         losses                               1,350,000         895,000        4,075,000       2,520,000
      Net gain on sales of commercial
         loans                                        0         (56,000)         (29,000)        (84,000)
      Stock option expense                       51,000               0          153,000               0
      Net change in:
         Accrued interest receivable         (1,391,000)     (1,489,000)      (2,164,000)     (2,395,000)
         Bank owned life insurance
            policies                           (298,000)       (258,000)        (872,000)       (737,000)
         Other assets                        (1,050,000)        429,000       (2,957,000)     (2,203,000)
         Accrued expenses and other
            liabilities                       1,256,000       1,959,000        2,740,000       4,570,000
                                           ------------    ------------    -------------   -------------
            Net cash used in operating
               activities                     5,901,000       6,508,000       18,548,000      16,825,000

CASH FLOWS FROM INVESTING ACTIVITIES
   Loan and lease originations and
      payments, net                         (40,716,000)    (64,620,000)    (151,091,000)   (172,519,000)
   Purchases of:
      Securities available for sale          (6,025,000)     (6,061,000)     (19,038,000)    (29,861,000)
      Securities held to maturity              (352,000)     (1,429,000)      (2,107,000)     (8,904,000)
      Federal Home Loan Bank stock                    0        (462,000)               0      (1,089,000)
   Proceeds from:
      Maturities, calls and repayments
         of available for sale
         securities                           1,720,000       3,299,000        5,807,000      12,815,000
      Maturities, calls and repayments
         of held to maturity securities               0               0          730,000         936,000
      Redemption of FHLB stock                  123,000               0          123,000               0
   Purchases of premises and equipment,
      net                                    (2,129,000)     (2,263,000)      (4,050,000)     (7,640,000)
   Purchases of bank owned life
      insurance policies                              0      (1,148,000)      (1,207,000)     (1,588,000)
                                           ------------    ------------    -------------   -------------
            Net cash from investing
               activities                   (47,379,000)    (72,684,000)    (170,833,000)   (207,850,000)

CASH FLOWS FROM FINANCING ACTIVITIES
   Net increase in deposits                  66,791,000      75,436,000      195,351,000     238,099,000
   Net increase in securities sold under
      agreements to repurchase                9,680,000       6,960,000        1,910,000       6,677,000
   Net decrease in federal funds
      purchased                             (11,400,000)              0       (9,600,000)    (15,000,000)
   Proceeds from new FHLB advances           15,000,000      25,000,000       65,000,000      65,000,000
   Maturities of FHLB advances              (30,000,000)    (25,000,000)     (80,000,000)    (50,000,000)
   Net increase in other borrowed money         190,000         142,000          800,000         602,000
   Employee stock purchase plan                  28,000          30,000           83,000          69,000
   Dividend reinvestment plan                    31,000          52,000           76,000         136,000
   Stock option exercises, net                   63,000          17,000          186,000          70,000
   Payment of cash dividends                 (1,042,000)       (834,000)      (2,994,000)     (2,349,000)
   Cash paid in lieu of fractional
      shares on stock dividend                        0               0           (4,000)         (4,000)
                                           ------------    ------------    -------------   -------------
      Net cash from financing activities     49,341,000      81,803,000      170,808,000     243,300,000
                                           ------------    ------------    -------------   -------------


          See accompanying notes to consolidated financial statements.


                                        7



                           MERCANTILE BANK CORPORATION
                CONSOLIDATED STATEMENTS OF CASH FLOWS (Continued)



                                            Three Months    Three Months    Nine Months     Nine Months
                                               Ended           Ended           Ended           Ended
                                           September 30,   September 30,   September 30,   September 30,
                                                2006            2005            2006            2005
                                           -------------   -------------   -------------   -------------
                                            (Unaudited)     (Unaudited)     (Unaudited)     (Unaudited)
                                                                               
Net change in cash and cash equivalents       7,863,000      15,627,000      18,523,000      52,275,000
Cash and cash equivalents at beginning
   of period                                 47,413,000      57,459,000      36,753,000      20,811,000
                                            -----------     -----------     -----------     -----------
CASH AND CASH EQUIVALENTS AT END OF
   PERIOD                                   $55,276,000     $73,086,000     $55,276,000     $73,086,000
                                            ===========     ===========     ===========     ===========
Supplemental disclosures of cash flow
   information
   Cash paid during the period for:
      Interest                              $18,306,000     $10,934,000     $48,483,000     $27,731,000
      Federal income tax                      2,880,000       1,882,000       8,755,000       6,357,000


          See accompanying notes to consolidated financial statements.


                                        8


                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

1.   SIGNIFICANT ACCOUNTING POLICIES

     Basis of Presentation: The unaudited financial statements for the three and
     nine months ended September 30, 2006 include the consolidated results of
     operations of Mercantile Bank Corporation and its consolidated
     subsidiaries. These subsidiaries include Mercantile Bank of Michigan ("our
     bank"), our bank's three subsidiaries, Mercantile Bank Mortgage Company,
     LLC ("our mortgage company"), Mercantile Bank Real Estate Co., LLC ("our
     real estate company"), and Mercantile Insurance Center, Inc. ("our
     insurance center"). These consolidated financial statements have been
     prepared in accordance with the instructions for Form 10-Q and Item 303(b)
     of Regulation S-K and do not include all disclosures required by accounting
     principles generally accepted in the United States of America for a
     complete presentation of our financial condition and results of operations.
     In the opinion of management, the information reflects all adjustments
     (consisting only of normal recurring adjustments) which are necessary in
     order to make the financial statements not misleading and for a fair
     presentation of the results of operations for such periods. The results for
     the periods ended September 30, 2006 should not be considered as indicative
     of results for a full year. For further information, refer to the
     consolidated financial statements and footnotes included in our annual
     report on Form 10-K for the year ended December 31, 2005.

     The Company formed a business trust, Mercantile Bank Capital Trust I ("the
     trust"), in 2004 to issue trust preferred securities. The Company issued
     subordinated debentures to the trust in return for the proceeds raised from
     the issuance of the trust preferred securities. In accordance with FASB
     Interpretation No. 46, the trust is not consolidated, but instead the
     Company reports the subordinated debentures issued to the trust as a
     liability.

     Earnings Per Share: Basic earnings per share is based on weighted average
     common shares outstanding during the period. Diluted earnings per share
     include the dilutive effect of additional potential common shares issuable
     under stock options. Options for 7,163 shares were antidilutive and were
     not included in determining diluted earnings per share for the three and
     nine month periods ended September 30, 2006.

     Stock Dividend: All per share amounts and average shares outstanding have
     been adjusted for all periods presented to reflect the 5% stock dividend
     distributed on May 16, 2006. The Statement of Changes in Shareholders'
     Equity reflects a transfer from retained earnings to common stock for the
     value of the shares distributed to the extent of available retained
     earnings.

     Allowance for Loan and Lease Losses: The allowance for loan and lease
     losses ("allowance") is a valuation allowance for probable incurred credit
     losses, increased by the provision for loan and lease losses and
     recoveries, and decreased by charge-offs. Management estimates the
     allowance balance required based on past loan loss experience, the nature
     and volume of the portfolio, information about specific borrower situations
     and estimated collateral values, and economic conditions. Allocations of
     the allowance may be made for specific loans and leases, but the entire
     allowance is available for any loan or lease that, in management's
     judgment, should be charged-off. Loan and lease losses are charged against
     the allowance when management believes the uncollectibility of a loan or
     lease balance is confirmed.


                                       9



                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

1.   SIGNIFICANT ACCOUNTING POLICIES (Continued)

     A loan or lease is impaired when full payment under the loan or lease terms
     is not expected. Impairment is evaluated in aggregate for smaller-balance
     loans of similar nature such as residential mortgage, consumer and credit
     card loans, and on an individual loan basis for other loans. If a loan or
     lease is impaired, a portion of the allowance is allocated so that the loan
     or lease is reported, net, at the present value of estimated future cash
     flows using the loan's or lease's existing rate or at the fair value of
     collateral if repayment is expected solely from the collateral. Loans and
     leases are evaluated for impairment when payments are delayed, typically 30
     days or more, or when serious deficiencies are identified within the credit
     relationship.

     Stock Options: Stock option plans are used to reward directors and
     employees and provide them with additional equity interest. Stock options
     granted to non-employee directors are at 125% of the market price on the
     date of grant, fully vest after five years and expire ten years from the
     date of grant. Stock options granted to employees are granted at the market
     price on the date of grant, generally fully vest after one year and expire
     ten years from the date of grant. Stock options granted to non-executive
     employees during 2005 vested about three weeks after being granted.

     The Stock Incentive Plan of 2006 ("Incentive Plan") was approved by
     shareholders at the annual meeting held on April 27, 2006. The Incentive
     Plan provides for the grant of equity-based incentives to eligible
     participants. The forms of long-term incentive compensation include stock
     options, stock appreciation rights, restricted stock units, restricted
     stock, stock awards and other awards based on or related to shares of
     Mercantile Bank Corporation common stock. The Incentive Plan provides for
     350,000 shares of Mercantile Bank Corporation common stock to be available
     for incentive awards under the Incentive Plan, combined with the 245,769
     shares available for issuance under previously authorized stock option
     plans, for a total of 595,769 shares.

     Prior to January 1, 2006, the Company accounted for stock-based
     compensation expense using the intrinsic value method as required by APB
     Opinion No. 25 "Accounting for Stock Issued to Employees" and as permitted
     by SFAS No. 123 "Accounting for Stock-Based Compensation." No compensation
     cost for stock options was reflected in net income for 2005, as all options
     granted had an exercise price equal to the market price of the underlying
     common stock at date of grant.

     On January 1, 2006, the Company adopted SFAS No. 123(R), which requires
     measurement of compensation cost for all stock-based awards be based on the
     grant-date fair value and recognition of compensation cost over the service
     period of stock-based awards, which is usually the same as the vesting
     period. The fair value of stock options is determined using the
     Black-Scholes valuation model, which is consistent with the Company's
     valuation methodology previously utilized for options in the footnote
     disclosures required under SFAS No. 123. The Company has adopted SFAS No.
     123(R) using the modified prospective method, which provides for no
     retroactive application to prior periods and no cumulative adjustment to
     equity accounts. As amended, this applies to awards granted or modified
     beginning with the first quarter of 2006. Compensation cost is also
     recorded for prior option grants that vest after the date of adoption. SFAS
     No. 123(R) also amends SFAS No. 95 "Statement of Cash Flows," and requires
     tax benefits relating to excess stock-based compensation deductions be
     presented in the consolidated statements of cash flows as financing cash
     inflows.


                                       10



                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

1.   SIGNIFICANT ACCOUNTING POLICIES (Continued)

     On March 29, 2005, the Securities and Exchange Commission ("SEC") published
     Staff Accounting Bulletin ("SAB") No. 107, which expressed the views of the
     Staff regarding interaction between SFAS No. 123(R) and certain SEC rules
     and regulations and provided the Staff's views regarding the valuation of
     stock-based payment arrangements for public companies. SAB No. 107 requires
     that stock-based compensation be classified in the same expense category as
     cash compensation. Accordingly, the Company has included stock-based
     compensation expense in salaries and employee benefits in the consolidated
     statements of income and comprehensive income.

     The adoption of SFAS No. 123(R) had the following impact on reported
     amounts compared with amounts that would have been reported using the
     intrinsic value method under previous accounting.



                              Three Months Ended September 30, 2006
                             ---------------------------------------
                                Using          SFAS
                               Previous       123(R)          As
                              Accounting   Adjustments     Reported
                             -----------   -----------   -----------
                                                
Income before taxes           $7,582,000    $(51,000)     $7,531,000
Income taxes                   2,329,000           0       2,329,000
                              ----------    --------      ----------
Net income                    $5,253,000    $(51,000)     $5,202,000
                              ==========    ========      ==========
Basic earnings per share      $     0.66    $  (0.01)     $     0.65
Diluted earnings per share    $     0.65    $  (0.01)     $     0.64




                               Nine Months Ended September 30, 2006
                             ---------------------------------------
                                Using          SFAS
                               Previous       123(R)          As
                              Accounting   Adjustments     Reported
                             -----------   -----------   ----------
                                                
Income before taxes          $22,185,000    $(153,000)   $22,032,000
Income taxes                   6,790,000            0      6,790,000
                             -----------    ---------    -----------
Net income                   $15,395,000    $(153,000)   $15,242,000
                             ===========    =========    ===========
Basic earnings per share     $      1.93    $   (0.02)   $      1.91
Diluted earnings per share   $      1.90    $   (0.02)   $      1.88



                                       11



                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

1.   SIGNIFICANT ACCOUNTING POLICIES (Continued)

     The following tables illustrate the effect on net income and earnings per
     share if expense had been measured using the fair value recognition
     provisions of SFAS No. 123.



                              Three Months Ended September 30, 2005
                             ---------------------------------------
                                                          Pro Forma
                                  As        Pro Forma    As If Under
                               Reported    Adjustments     SFAS 123
                             -----------   -----------   -----------
                                                
Income before taxes           $6,187,000    $(94,000)     $6,093,000
Income taxes                   1,887,000           0       1,887,000
                              ----------    --------      ----------
Net income                    $4,300,000    $(94,000)     $4,206,000
                              ==========    ========      ==========
Basic earnings per share      $     0.54    $  (0.01)     $     0.53
Diluted earnings per share    $     0.53    $  (0.01)     $     0.52




                               Nine Months Ended September 30, 2005
                             ---------------------------------------
                                                          Pro Forma
                                  As        Pro Forma    As If Under
                               Reported    Adjustments     SFAS 123
                             -----------   -----------   -----------
                                                
Income before taxes          $19,258,000    $(281,000)   $18,977,000
Income taxes                   5,906,000            0      5,906,000
                             -----------    ---------    -----------
Net income                   $13,352,000    $(281,000)   $13,071,000
                             ===========    =========    ===========
Basic earnings per share     $      1.68    $   (0.04)   $      1.64
Diluted earnings per share   $      1.64    $   (0.03)   $      1.61



                                       12



                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

1.   SIGNIFICANT ACCOUNTING POLICIES (Continued)

     The following is activity under the stock option plans:



                                      Nine Months Ended
                                      September 30, 2006
                                     -------------------
                                                Weighted
                                                 Average
                                                Exercise
                                      Shares      Price
                                     --------   --------
                                          
Outstanding at beginning of period    315,302    $21.83
Granted                                     0        NA
Exercised                              59,126     12.76
Forfeited                               2,204     33.55
                                      -------    ------
Outstanding at end of period          253,972    $23.84
                                      =======    ======
Exercisable at end of period          211,320    $22.32
                                      =======    ======


     The aggregate intrinsic value of all options outstanding at September 30,
     2006 was $4.0 million.

     The aggregate intrinsic value of all options that were exercisable at
     September 30, 2006 was $3.6 million.

     The aggregate intrinsic value of stock options exercised during the first
     nine months of 2006 was $1.6 million.

     The weighted average fair value of the stock options for 2,479 shares that
     vested during the first nine months of 2006 was $10.90 per share.


                                       13


                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

1.   SIGNIFICANT ACCOUNTING POLICIES (Continued)

     Stock options outstanding as of September 30, 2006:



                                          Outstanding
                               --------------------------------       Exercisable
                                           Weighted               ------------------
                                           Average     Weighted             Weighted
                                          Remaining     Average              Average
                                         Contractual   Exercise             Exercise
                               Shares        Life        Price     Shares     Price
                               -------   -----------   --------   -------   --------
                                                             
$4.00 - $8.00                    8,952    0.8 Years     $ 7.46      8,952    $ 7.46
$8.01 - $12.00                  42,208    3.3 Years       9.20     42,208      9.20
$12.01 - $16.00                 29,306    5.0 Years      13.07     29,306     13.07
$16.01 - $20.00                 39,785    5.9 Years      16.83     32,153     16.94
$20.01 - $24.00                  7,272    6.0 Years      21.19          0        NA
$24.01 - $28.00                 31,170    7.1 Years      27.94     31,170     27.94
$32.01 - $36.00                 41,783    7.9 Years      35.29     34,847     35.36
$36.01 - $40.00                 46,333    9.1 Years      37.68     32,684     37.68
$40.01 - $44.00                  7,163    8.0 Years      42.29          0        NA
                               -------                            -------
Outstanding at end of period   253,972    6.3 Years     $23.84    211,320    $22.32
                               =======                            =======


     The compensation cost yet to be recognized for stock option grants that
     have been awarded but not vested is $51,000 for the remainder of 2006, and
     $27,000, $17,000 and $8,000 for 2007, 2008, and 2009, respectively.

     Newly Issued but Not Yet Effective Accounting Standards: In June 2006, the
     FASB issued Interpretation No. 48, Accounting for Uncertainty in Income
     Taxes - an interpretation of FASB Statement No. 109 ("FIN 48"), which
     clarifies the accounting for uncertainty in income taxes recognized in a
     company's financial statements in accordance with SFAS 109, Accounting for
     Income Taxes. FIN 48 prescribes a recognition and measurement threshold for
     a tax position taken or expected to be taken in a tax return. FIN 48 also
     provides guidance on derecognition, classification, interest and penalties,
     accounting in interim periods, disclosure and transition. FIN 48 is
     effective for fiscal years beginning after December 15, 2006. The Company
     has not completed its evaluation of the impact of the adoption of FIN 48.

     In September 2006, the Securities and Exchange Commission released Staff
     Accounting Bulletin ("SAB") 108. This SAB provides guidance to registrants
     in the determination of what is material to their financial statements.
     This SAB is required to be applied to financial statements issued after
     November 15, 2006. Upon adoption, the cumulative effect of applying the new
     guidance is to be reflected as an adjustment to opening retained earnings
     as of the beginning of the current fiscal year. The Company has not
     completed its evaluation of the impact of SAB 108.


                                       14



                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

2.   LOANS AND LEASES

     Our total loans and leases at September 30, 2006 were $1,710.3 million
     compared to $1,561.8 million at December 31, 2005, an increase of $148.5
     million, or 9.5%. The components of our outstanding balances at September
     30, 2006 and December 31, 2005, and the percentage changes in loans and
     leases from the end of 2005 to the end of the third quarter 2006 are as
     follows:



                                 September 30, 2006        December 31, 2005       Percent
                               ----------------------   ----------------------    Increase/
                                   Balance        %         Balance        %     (Decrease)
                               --------------   -----   --------------   -----   ----------
                                                                  
Real Estate:
   Construction and land
      development              $  259,409,000    15.2%  $  226,544,000    14.5%     14.5%
   Secured by 1-4 family
      properties                  128,932,000     7.5      128,111,000     8.2       0.6
   Secured by multi-family
      properties                   38,438,000     2.2       30,114,000     2.0      27.6
   Secured by nonresidential
      properties                  821,389,000    48.0      714,963,000    45.8      14.9
Commercial                        453,982,000    26.6      454,911,000    29.1      (0.2)
Leases                              1,046,000     0.1        1,786,000     0.1     (41.4)
Consumer                            7,072,000     0.4        5,383,000     0.3      31.4
                               --------------   -----   --------------   -----     -----
   Total loans and leases      $1,710,268,000   100.0%  $1,561,812,000   100.0%      9.5%
                               ==============   =====   ==============   =====     =====


3.   ALLOWANCE FOR LOAN AND LEASE LOSSES

     The following is a summary of the change in our allowance for loan and
     lease losses account for the three and nine months ended September 30:



                                     Three months ended              Nine months ended
                               -----------------------------   -----------------------------
                               September 30,   September 30,   September 30,   September 30,
                                    2006            2005            2006            2005
                               -------------   -------------   -------------   -------------
                                                                   
Balance at beginning of
 period                         $21,507,000     $18,856,000     $20,527,000     $17,819,000
   Charge-offs                   (1,250,000)       (338,000)     (3,113,000)     (1,042,000)
   Recoveries                       331,000         158,000         449,000         274,000
   Provision for loan and
      lease losses                1,350,000         895,000       4,075,000       2,520,000
                                -----------     -----------     -----------     -----------
Balance at September 30         $21,938,000     $19,571,000     $21,938,000     $19,571,000
                                ===========     ===========     ===========     ===========



                                       15



                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

4.   PREMISES AND EQUIPMENT - NET

     Premises and equipment are comprised of the following:



                               September 30,   December 31,
                                    2006           2005
                               -------------   ------------
                                         
Land and improvements           $ 9,565,000     $ 7,135,000
Buildings and leasehold
   improvements                  19,810,000      18,450,000
Furniture and equipment          10,609,000      10,351,000
                                -----------     -----------
                                 39,984,000      35,936,000
Less: accumulated
   depreciation                   7,675,000       5,730,000
                                -----------     -----------
Premises and equipment, net     $32,309,000     $30,206,000
                                ===========     ===========


     Depreciation expense amounted to $644,000 during the third quarter of 2006,
     compared to $590,000 in the third quarter of 2005. Depreciation expense
     amounted to $1,947,000 during the first nine months of 2006, compared to
     $1,422,000 during the first nine months of 2005.

5.   DEPOSITS

     Our total deposits at September 30, 2006 were $1,614.7 million compared to
     $1,419.4 million at December 31, 2005, an increase of $195.3 million, or
     13.8%. The components of our outstanding balances at September 30, 2006 and
     December 31, 2005, and percentage change in deposits from the end of 2005
     to the end of the third quarter 2006 are as follows:



                               September 30, 2006        December 31, 2005       Percent
                             ----------------------   ----------------------    Increase/
                                 Balance        %         Balance        %     (Decrease)
                             --------------   -----   --------------   -----   ----------
                                                                
Noninterest-bearing demand   $  115,269,000     7.1%  $  120,828,000     8.5%     (4.6)%
Interest-bearing checking        41,224,000     2.5       39,792,000     2.8       3.6
Money market                      9,565,000     0.6       10,344,000     0.7      (7.5)
Savings                          78,239,000     4.8      106,247,000     7.5     (26.4)
Time, under $100,000             42,892,000     2.7       23,906,000     1.7      79.4
Time, $100,000 and over         283,455,000    17.6      155,401,000    11.0      82.4
                             --------------   -----   --------------   -----     -----
                                570,644,000    35.3      456,518,000    32.2      25.0
Out-of-area time, under
   $100,000                      76,600,000     4.8       80,048,000     5.6      (4.3)
Out-of-area time,
   $100,000 and over            967,459,000    59.9      882,786,000    62.2       9.6
                             --------------   -----   --------------   -----     -----
                              1,044,059,000    64.7      962,834,000    67.8       8.4
                             --------------   -----   --------------   -----     -----
   Total deposits            $1,614,703,000   100.0%  $1,419,352,000   100.0%     13.8%
                             ==============   =====   ==============   =====     =====



                                       16



                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

6.   SHORT-TERM BORROWINGS

     Information relating to our securities sold under agreements to repurchase
     follows:



                             September 30,   December 31,
                                  2006           2005
                             -------------   ------------
                                       
Outstanding balance at end
   of period                  $74,111,000    $72,201,000
Average interest rate at
   end of period                     3.88%          3.31%

Average balance during the
   period                     $69,217,000    $60,743,000
Average interest rate
   during the period                 3.63%          2.63%

Maximum month end balance
   during the period          $79,443,000    $74,639,000


     Securities sold under agreements to repurchase ("repurchase agreements")
     generally have original maturities of less than one year. Repurchase
     agreements are treated as financings and the obligations to repurchase
     securities sold are reflected as liabilities. Securities involved with the
     agreements are recorded as assets of our bank and are primarily held in
     safekeeping by correspondent banks. Repurchase agreements are offered
     principally to certain large deposit customers as deposit equivalent
     investments.

7.   FEDERAL HOME LOAN BANK ADVANCES

     Our outstanding balances at September 30, 2006 and December 31, 2005 were
     as follows:



                              September 30,   December 31,
                                   2006           2005
                              -------------   ------------
                                        
Maturities October 2006
   through May 2008, fixed
   rates from 3.42% to
   5.69%, averaging 4.72%      $115,000,000   $          0
Maturities January 2006
   through May 2008,
   fixed rates from 2.13%
   to 4.92%, averaging
   3.68%                                       120,000,000
Maturities in May 2006,
   floating rates tied to
   Libor indices,
   averaging 4.42%                              10,000,000
                               ------------   ------------
      Total Federal Home
         Loan Bank advances    $115,000,000   $130,000,000
                               ============   ============


     Each advance is payable at its maturity date, and is subject to a
     prepayment fee if paid prior to the maturity date. The advances are
     collateralized by residential mortgage loans, first mortgage liens on
     multi-family residential property loans, first mortgage liens on commercial
     real estate property loans, and substantially all other assets of our bank,
     under a blanket lien arrangement. Our borrowing line of credit as of
     September 30, 2006 totaled $321.9 million, with availability of $195.8
     million.


                                       17



                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

7.   FEDERAL HOME LOAN BANK ADVANCES (Continued)

     Maturities of FHLB advances currently outstanding during the next five
     years are:


    
2006   $35,000,000
2007    65,000,000
2008    15,000,000
2009             0
2010             0


8.   COMMITMENTS AND OFF-BALANCE-SHEET RISK

     Our bank is a party to financial instruments with off-balance-sheet risk in
     the normal course of business to meet the financing needs of our customers.
     These financial instruments include commitments to extend credit and
     standby letters of credit. Loan commitments to extend credit are agreements
     to lend to a customer as long as there is no violation of any condition
     established in the contract. Standby letters of credit are conditional
     commitments issued by our bank to guarantee the performance of a customer
     to a third party. Commitments generally have fixed expiration dates or
     other termination clauses and may require payment of a fee. Since many of
     the commitments are expected to expire without being drawn upon, the total
     commitment amounts do not necessarily represent future cash requirements.

     These instruments involve, to varying degrees, elements of credit risk in
     excess of the amount recognized, if any, in the balance sheet. Our bank's
     maximum exposure to loan loss in the event of nonperformance by the other
     party to the financial instrument for commitments to extend credit and
     standby letters of credit is represented by the contractual notional amount
     of those instruments. Our bank uses the same credit policies in making
     commitments and conditional obligations as it does for on-balance sheet
     instruments. Collateral, such as accounts receivable, securities,
     inventory, property and equipment, is generally obtained based on
     management's credit assessment of the borrower. If required, estimated loss
     exposure resulting from these instruments is expensed and recorded as a
     liability. The balance of the liability account was $0.5 million as of
     September 30, 2006 and December 31, 2005.

     A summary of the contractual amounts of our financial instruments with
     off-balance-sheet risk at September 30, 2006 and December 31, 2005 follows:



                             September 30,   December 31,
                                  2006           2005
                             -------------   ------------
                                       
Commercial unused lines of
   credit                     $333,437,000   $303,115,000
Unused lines of credit
   secured by 1-4 family
   residential properties       28,751,000     27,830,000
Credit card unused lines
   of credit                     8,332,000      7,971,000
Other consumer unused
   lines of credit               7,500,000     10,791,000
Commitments to make loans       91,883,000     83,280,000
Standby letters of credit       65,044,000     59,058,000
                              ------------   ------------
      Total loan and lease
         commitments          $534,947,000   $492,045,000
                              ============   ============



                                       18



                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)


9.   REGULATORY MATTERS

     We are subject to regulatory capital requirements administered by federal
     banking agencies. Capital adequacy guidelines and prompt corrective action
     regulations involve quantitative measures of assets, liabilities, and
     certain off-balance-sheet items calculated under regulatory accounting
     practices. Capital amounts and classifications are also subject to
     qualitative judgments by regulators about components, risk weightings, and
     other factors, and the regulators can lower classifications in certain
     cases. Failure to meet various capital requirements can initiate regulatory
     action that could have a direct material effect on our financial
     statements.

     The prompt corrective action regulations provide five classifications,
     including well capitalized, adequately capitalized, undercapitalized,
     significantly undercapitalized, and critically undercapitalized, although
     these terms are not used to represent overall financial condition. If not
     well capitalized, regulatory approval is required to accept brokered
     deposits. If undercapitalized, capital distributions are limited, as is
     asset growth and expansion, and plans for capital restoration are required.

     Our actual capital levels and minimum required levels were (dollars in
     thousands):



                                                                     Minimum Required
                                                                        to be Well
                                                 Minimum Required    Capitalized Under
                                                   for Capital       Prompt Corrective
                                  Actual        Adequacy Purposes   Action Regulations
                             ----------------   -----------------   ------------------
                              Amount    Ratio     Amount    Ratio     Amount    Ratio
                             --------   -----    --------   -----    --------   -----
                                                              
September 30, 2006
   Total capital (to risk
     weighted assets)
       Consolidated          $223,213    11.6%   $153,858     8.0%   $     NA     NA
       Bank                   219,573    11.4     153,674     8.0     192,092   10.0%
   Tier 1 capital (to risk
     weighted assets)
       Consolidated           201,275    10.5      76,929     4.0          NA     NA
       Bank                   197,635    10.3      76,837     4.0     115,256    6.0
   Tier 1 capital (to
     average assets)
       Consolidated           201,275    10.1      79,369     4.0          NA     NA
       Bank                   197,635    10.0      79,321     4.0      99,151    5.0
 


                                       19


                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

9.   REGULATORY MATTERS (Continued)



                                                                     Minimum Required
                                                                        to be Well
                                                 Minimum Required     Capitalized Under
                                                   for Capital       Prompt Corrective
                                  Actual        Adequacy Purposes   Action Regulations
                             ----------------   -----------------   ------------------
                              Amount    Ratio     Amount    Ratio     Amount    Ratio
                             --------   -----    --------   -----    --------   -----
                                                              
December 31, 2005
   Total capital (to risk
      weighted assets)
      Consolidated           $209,060    12.0%   $139,337     8.0%   $     NA     NA
      Bank                    205,642    11.8     139,158     8.0     173,947   10.0%
   Tier 1 capital (to risk
      weighted assets)
      Consolidated            188,533    10.8      69,669     4.0          NA     NA
      Bank                    185,115    10.6      69,579     4.0     104,368    6.0
   Tier 1 capital (to
      average assets)
      Consolidated            188,533    10.5      72,163     4.0          NA     NA
      Bank                    185,115    10.3      72,100     4.0      90,124    5.0


     Our consolidated capital levels as of September 30, 2006 and December 31,
     2005 include the $32.0 million in trust preferred securities issued by the
     trust subject to certain limitations. Federal Reserve guidelines limit the
     amount of trust preferred securities which can be included in our Tier 1
     capital to 25% of total Tier 1 capital. As of September 30, 2006 and
     December 31, 2005, all $32.0 million of the trust preferred securities were
     included as Tier 1 capital.

     Our and our bank's ability to pay cash and stock dividends is subject to
     limitations under various laws and regulations and to prudent and sound
     banking practices. We declared a 5% stock dividend on April 11, 2006, that
     was distributed on May 16, 2006 to record holders as of April 24, 2006. All
     earnings per share and dividend per share information have been adjusted
     for the 5% stock dividend. We have also paid three cash dividends on our
     common stock during 2006. On January 10, 2006, we declared a $0.12 per
     share cash dividend on our common stock, which was paid on March 10, 2006
     to record holders as of February 10, 2006. On April 11, 2006, we declared a
     $0.13 per share cash dividend on our common stock, which was paid on June
     9, 2006 to record holders as of May 17, 2006. On July 11, 2006, we declared
     a $0.13 per share cash dividend on our common stock, which was paid on
     September 8, 2006 to record holders as of August 10, 2006. On October 10,
     2006, we declared a $0.13 per share cash dividend on our common stock,
     which is payable on December 8, 2006 to record holders as of November 10,
     2006.


                                       20



                           MERCANTILE BANK CORPORATION
                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                                   (Unaudited)

10.  BENEFIT PLANS

     We sponsor an employee stock purchase plan which allows employees to use
     after-tax payroll dollars to purchase our common stock on a quarterly
     basis. We have registered 30,387 shares of common stock to be issued and
     purchased under the plan; however, the plan allows for shares to be
     purchased directly from us or on the open market. During the nine months
     ended September 30, 2006, we issued 2,144 shares under the plan.


                                       21



                           MERCANTILE BANK CORPORATION

ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATION

FORWARD LOOKING STATEMENTS

This report contains forward-looking statements that are based on management's
beliefs, assumptions, current expectations, estimates and projections about the
financial services industry, the economy, and our company. Words such as
"anticipates", "believes", "estimates", "expects", "forecasts", "intends", "is
likely", "plans", "projects", and variations of such words and similar
expressions, are intended to identify such forward-looking statements. These
statements are not guarantees of future performance and involve certain risks,
uncertainties and assumptions ("Future Factors") that are difficult to predict
with regard to timing, extent, likelihood and degree of occurrence. Therefore,
actual results and outcomes may materially differ from what may be expressed or
forecasted in such forward-looking statements. We undertake no obligation to
update, amend, or clarify forward looking-statements, whether as a result of new
information, future events (whether anticipated or unanticipated), or otherwise.

Future Factors include, among others, changes in interest rates and interest
rate relationships; demand for products and services; the degree of competition
by traditional and non-traditional competitors; changes in banking regulation;
changes in tax laws; changes in prices, levies, and assessments; the impact of
technological advances; governmental and regulatory policy changes; the outcomes
of contingencies; trends in customer behavior as well as their ability to repay
loans; and changes in the national and local economy. These are representative
of the Future Factors that could cause a difference between an ultimate actual
outcome and a forward-looking statement.

INTRODUCTION

The following discussion compares the financial condition of Mercantile Bank
Corporation and its consolidated subsidiaries, Mercantile Bank of Michigan ("our
bank"), our bank's three subsidiaries Mercantile Bank Mortgage Company, LLC
("our mortgage company"), Mercantile Bank Real Estate Co., LLC ("our real estate
company") and Mercantile Insurance Center, Inc. ("our insurance center"), at
September 30, 2006 to December 31, 2005 and the results of operations for the
three and nine months ended September 30, 2006 and September 30, 2005. This
discussion should be read in conjunction with the interim consolidated financial
statements and footnotes included in this report. Unless the text clearly
suggests otherwise, references in this report to "us," "we," "our," or "the
company" include Mercantile Bank Corporation and its consolidated subsidiaries
referred to above.

CRITICAL ACCOUNTING POLICIES

Generally accepted accounting principles are complex and require management to
apply significant judgment to various accounting, reporting and disclosure
matters. Management must use assumptions and estimates to apply these principles
where actual measurements are not possible or practical. Management's Discussion
and Analysis of Financial Condition and Results of Operations should be read in
conjunction with our unaudited financial statements included in this report. For
a complete discussion of our significant accounting policies, see footnotes to
our Consolidated Financial Statements included on pages F-35 through F-40 in our
Form 10-K for the fiscal year ended December 31, 2005 (Commission file number
000-26719). Below is a discussion of our Allowance for Loan and Lease Losses
policy. This policy is critical because it is highly dependent upon subjective
or complex judgments, assumptions and estimates. Changes in such estimates may
have a significant impact on the financial statements, and actual results may
differ from those estimates. Management has reviewed the application of this
policy with the Audit Committee of the company's Board of Directors.


                                       22



                           MERCANTILE BANK CORPORATION

Allowance for Loan and Lease Losses: The allowance for loan and lease losses
("allowance") is a valuation allowance for probable incurred credit losses,
increased by the provision for loan and lease losses and recoveries, and
decreased by charge-offs. Management estimates the allowance balance required
based on past loan loss experience, the nature and volume of the portfolio,
information about specific borrower situations and estimated collateral values,
and economic conditions. Allocations of the allowance may be made for specific
loans and leases, but the entire allowance is available for any loan or lease
that, in management's judgment, should be charged-off. Loan and lease losses are
charged against the allowance when management believes the uncollectibility of a
loan or lease balance is confirmed.

A loan or lease is impaired when full payment under the loan or lease terms is
not expected. Impairment is evaluated in aggregate for smaller-balance loans of
similar nature such as residential mortgage, consumer and credit card loans, and
on an individual loan basis for other loans. If a loan or lease is impaired, a
portion of the allowance is allocated so that the loan or lease is reported,
net, at the present value of estimated future cash flows using the loan's or
lease's existing rate or at the fair value of collateral if repayment is
expected solely from the collateral. Loans and leases are evaluated for
impairment when payments are delayed, typically 30 days or more, or when serious
deficiencies are identified within the credit relationship.

FINANCIAL CONDITION

During the first nine months of 2006, our assets increased from $1,838.2 million
on December 31, 2005, to $2,026.8 million on September 30, 2006. This represents
an increase in total assets of $188.6 million, or 10.3%. The asset growth was
comprised primarily of a $147.0 million increase in net loans, an $18.5 million
increase in cash and cash equivalents and a $14.0 million increase in
securities. The growth in total assets was primarily funded by a $195.3 million
increase in deposits, partially offset by a $15.0 million decrease in Federal
Home Loan Bank advances and a $9.6 million decrease in federal funds purchased.

Commercial loans and leases increased by $145.9 million during the first nine
months of 2006, and at September 30, 2006, totaled $1,574.3 million, or 92.0% of
the total loan and lease portfolio. The continued significant concentration of
the loan and lease portfolio in commercial loans and leases and the rapid growth
of this portion of our lending business is consistent with our stated strategy
of focusing a substantial amount of efforts on "wholesale" banking. Corporate
and business lending continues to be an area of expertise of our senior
management team, and our commercial lenders have extensive commercial lending
experience, with most having at least 10 years' experience. Of each of the loan
categories that we originate, commercial loans and leases are most efficiently
originated and managed; thus limiting overhead costs by necessitating the
attention of fewer full-time employees. Our commercial lending business
generates the greatest amount of local deposits, and is our primary source of
demand deposits.

Residential mortgage loans and consumer loans increased by $0.8 million and $1.7
million, respectively, during the first nine months of 2006. As of September 30,
2006, residential mortgage and consumer loans totaled a combined $136.0 million,
or 8.0% of the total loan and lease portfolio. Although we plan to increase our
non-commercial loan portfolios in future periods, given our wholesale banking
strategy, we expect the commercial sector of our lending efforts and resultant
assets to remain the dominant loan portfolio category.


                                       23



                           MERCANTILE BANK CORPORATION

Management believes the quality of our loan and lease portfolio remains strong.
Net loan and lease charge-offs during the first nine months of 2006 totaled $2.7
million, or 0.22% of average total loans and leases on an annualized basis.
During the first nine months of 2005, net loan and lease charge-offs totaled
$0.8 million, or 0.07% of average total loans and leases on an annualized basis.
Nonperforming assets at September 30, 2006 totaled $9.4 million, or 0.47% of
period-ending total assets. Nonperforming assets at December 31, 2005 totaled
$4.0 million, or 0.22% of period-ending total assets, while nonperforming assets
at September 30, 2005 totaled $2.1 million, or 0.12% of period-ending total
assets.

We believe we have instilled a strong credit culture within our lending
departments as it pertains to the underwriting and administration processes,
which in part is reflected in our low loan and lease net charge-off and
delinquency ratios. Over 98% of the loan portfolio consists of loans extended
directly to companies and individuals doing business and residing within our
market areas. The remaining portion is comprised of commercial loans
participated with certain commercial banks outside the immediate areas, which we
underwrite using the same loan underwriting criteria as though our bank was the
originating bank.

Securities increased $14.0 million during the first nine months of 2006.
Purchases during the first nine months of 2006 totaled $21.1 million, while
proceeds from the maturities, calls and repayments of securities and the
redemption of Federal Home Loan Bank of Indianapolis ("FHLBI") stock totaled
$6.7 million. Our securities portfolio primarily consists of U.S. Government
Agency bonds, mortgage-backed securities issued or guaranteed by U.S. Government
Agencies, investment-grade tax-exempt municipal securities and FHLBI stock.

Cash and cash equivalents increased $18.5 million during the first nine months
of 2006, totaling $55.3 million on September 30, 2006. Cash and due from bank
balances were up $2.9 million and federal funds sold increased $16.0 million.
Our commercial lending and wholesale funding focus results in relatively large
day-to-day fluctuations of our cash and cash equivalent balances. Average cash
and cash equivalents during the first nine months of 2006 equaled $48.0 million.

Premises and equipment at September 30, 2006 equaled $32.3 million, an increase
of $2.1 million over the past nine months. Purchases of premises and equipment
during the first nine months of 2006 totaled $4.0 million, primarily reflecting
the initial construction costs of our new banking facility located in East
Lansing, Michigan. Depreciation expense during the first nine months of 2006
equaled $1.9 million.

Deposits increased $195.3 million during the first nine months of 2006, totaling
$1,614.7 million at September 30, 2006. Local deposits increased $114.1 million,
while out-of-area deposits increased $81.2 million. As a percent of total
deposits, local deposits increased from 32.2% on December 31, 2005, to 35.3% on
September 30, 2006. Noninterest-bearing demand deposits, comprising 7.1% of
total deposits, decreased $5.6 million during the first nine months of 2006.
Savings deposits (4.8% of total deposits) decreased $28.0 million,
interest-bearing checking deposits (2.5% of total deposits) increased $1.4
million and money market deposit accounts (0.6% of total deposits) decreased
$0.8 million during the first nine months of 2006. Local certificates of
deposit, comprising 20.3% of total deposits, increased by $147.0 million during
the first nine months of 2006. The increase in local certificates of deposit is
primarily attributable to increases in balances from municipalities and
transfers of monies by consumer and commercial customers from savings accounts
to certificates of deposit products, the latter of which reflecting that rates
offered on certificates of deposit have risen at a faster pace than the rates
offered on savings accounts.


                                       24



                           MERCANTILE BANK CORPORATION

Out-of-area deposits increased $81.2 million during the first nine months of
2006, totaling $1,044.1 million as of September 30, 2006. Out-of-area deposits
consist primarily of certificates of deposit obtained from depositors located
outside our market areas and placed by deposit brokers for a fee, but also
include certificates of deposit obtained from the deposit owners directly.
Out-of-area deposits are utilized to support our asset growth, and are generally
a lower cost source of funds when compared to the deposit interest rates that
would have to be offered in the local markets to generate a sufficient level of
funds. During the first nine months of 2006, rates paid on new out-of-area
certificates of deposit were generally similar to the rates paid on new
certificates of deposit issued to local customers. Overhead costs associated
with the out-of-area deposits are considerably less than the overhead costs that
would be incurred to administer a similar level of local deposits. Although
local deposits have and are expected to increase as new business, governmental
and consumer deposit relationships are established, our relatively high reliance
on out-of-area deposits is expected to continue.

Securities sold under agreements to repurchase ("repurchase agreements")
increased $1.9 million during the first nine months of 2006, totaling $74.1
million as of September 30, 2006. As part of our sweep account program,
collected funds from certain business noninterest-bearing checking accounts are
invested into over-night interest-bearing repurchase agreements. Although not
considered a deposit account and therefore not afforded federal deposit
insurance, the repurchase agreements have characteristics very similar to that
of our business checking deposit accounts.

Federal funds purchased declined by $9.6 million during the first nine months of
2006, with a zero balance as of September 30, 2006. Advances obtained from the
FHLBI totaled $115.0 million as of September 30, 2006, a decrease of $15.0
million from the $130.0 million outstanding on December 31, 2005. The advances
are collateralized by residential mortgage loans, first mortgage liens on
multi-family residential property loans and first mortgage liens on commercial
real estate property loans, and substantially all other assets of our bank,
under a blanket lien arrangement. Our borrowing line of credit as of September
30, 2006 totaled $321.9 million, with availability of $195.8 million. FHLBI
advances, along with out-of-area deposits, are the primary components of our
wholesale funding program.

LIQUIDITY

Liquidity is measured by our ability to raise funds through deposits, borrowed
funds, capital or cash flow from the repayment of loans and securities. These
funds are used to meet deposit withdrawals, maintain reserve requirements, fund
loans and support our operations. Liquidity is primarily achieved through the
growth of deposits (both local and out-of-area), advances from the FHLBI and
federal funds purchased, as well as liquid assets such as securities available
for sale, matured securities, and federal funds sold. Asset and liability
management is the process of managing our balance sheet to achieve a mix of
earning assets and liabilities that maximizes profitability, while providing
adequate liquidity.

Our liquidity strategy is to fund loan growth with deposits, repurchase
agreements and FHLBI advances, and to maintain an adequate level of short- and
medium-term investments to meet typical daily loan and deposit activity.
Although deposit and repurchase agreement growth from customers located in our
market areas has generally consistently increased, this growth has not been
sufficient to meet our substantial loan growth and provide monies for additional
investing activities. To assist in providing the additional needed funds, we
have regularly obtained monies from wholesale funding sources. Wholesale funds,
primarily comprised of certificates of deposit from customers outside of our
market areas and advances from the FHLBI, totaled $1,159.1 million, or 64.3% of
combined deposits and borrowed funds as of September 30, 2006. As of December
31, 2005, wholesale funds totaled $1,092.8 million, or 67.0% of combined
deposits and borrowed funds. Reliance on wholesale funds is expected to continue
due to our anticipated future asset growth.


                                       25



                           MERCANTILE BANK CORPORATION

As a member of the FHLBI, our bank has access to the FHLBI's borrowing programs.
At September 30, 2006, advances from the FHLBI totaled $115.0 million, down from
the $130.0 million outstanding at December 31, 2005. Based on available
collateral at September 30, 2006, our bank could borrow an additional $195.8
million from the FHLBI.

Our bank has the ability to borrow money on a daily basis through correspondent
banks via established unsecured federal funds purchased lines, totaling $72.0
million as of September 30, 2006. The average balance of federal funds purchased
during the first nine months of 2006 equaled $3.8 million, compared to a $9.6
million average federal funds sold position during the same time period.

In addition to typical loan funding and deposit flow, we must maintain liquidity
to meet the demands of certain unfunded loan commitments and standby letters of
credit. As of September 30, 2006, our bank had a total of $469.9 million in
unfunded loan commitments and $65.0 million in unfunded standby letters of
credit. Of the total unfunded loan commitments, $378.0 million were commitments
available as lines of credit to be drawn at any time as customers' cash needs
vary, and $91.9 million were for loan commitments expected to close and become
funded within the next twelve months. We monitor fluctuations in loan balances
and commitment levels, and include such data in managing our overall liquidity.

CAPITAL RESOURCES

Shareholders' equity is a noninterest-bearing source of funds that provides
support for asset growth. Shareholders' equity increased by $12.4 million during
the first nine months of 2006, from $155.1 million on December 31, 2005, to
$167.5 million at September 30, 2006. The increase is primarily attributable to
net income of $15.2 million recorded during the first nine months of 2006.
Shareholders' equity also increased $0.3 million from the issuance of new shares
of common stock resulting from our dividend reinvestment plan, employee stock
purchase plan and stock option exercises. Shareholders' equity was negatively
impacted during the first nine months of 2006 by the payment of cash dividends
totaling $3.0 million and a $0.3 million mark-to-market adjustment for available
for sale securities as defined in SFAS No. 115.

We are subject to regulatory capital requirements primarily administered by
federal bank regulatory agencies. Failure to meet the various capital
requirements can initiate regulatory action that could have a direct material
effect on the financial statements. The capital ratios of the company and our
bank as of September 30, 2006 and December 31, 2005 are disclosed under Note 9
of the Notes to Consolidated Financial Statements.

Our and our bank's ability to pay cash and stock dividends is subject to
limitations under various laws and regulations and to prudent and sound banking
practices. We declared a 5% stock dividend on April 11, 2006, that was
distributed on May 16, 2006 to record holders as of April 24, 2006. All earnings
per share and cash dividend per share information have been adjusted for the 5%
stock dividend. We paid a $0.12 per share cash dividend on March 10, 2006 and a
$0.13 per share cash dividend on June 9, 2006 and September 8, 2006. On October
10, 2006, we declared a $0.13 per share cash dividend payable on December 8,
2006 to record holders as of November 10, 2006.


                                       26



                           MERCANTILE BANK CORPORATION

RESULTS OF OPERATIONS

Net income for the third quarter of 2006 was $5.2 million ($0.65 per basic share
and $0.64 per diluted share), which represents a 21.0% increase over net income
of $4.3 million ($0.54 per basic share and $0.53 per diluted share) recorded
during the third quarter of 2005. Net income for the first nine months of 2006
was $15.2 million ($1.91 per basic share and $1.88 per diluted share), which
represents a 14.2% increase over net income of $13.4 million ($1.68 per basic
share and $1.64 per diluted share) recorded during the first nine months of
2005. The improvement in net income during both time periods is primarily the
result of higher net interest income and improved operating efficiency, which
more than offset a higher provision expense.

Interest income during the third quarter of 2006 was $35.7 million, an increase
of 33.3% over the $26.8 million earned during the third quarter of 2005.
Interest income during the first nine months of 2006 was $100.5 million, an
increase of 38.0% over the $72.8 million earned during the first nine months of
2005. The growth in interest income during both time periods is primarily
attributable to growth in earning assets and an increased interest rate
environment. During the third quarter of 2006, earning assets averaged $1,881.9
million, $234.6 million higher than average earning assets of $1,647.3 million
during the third quarter of 2005. Average loans were up $223.9 million and
securities increased $13.6 million. During the first nine months of 2006,
earning assets averaged $1,834.5 million, $253.4 million higher than average
earning assets of $1,581.0 million during the same time period in 2005. Average
loans were up $233.5 million and securities increased $18.3 million. Also
positively impacting the growth in interest income was the increased yield on
earning assets. During the third quarter of 2006 and 2005, earning assets had a
weighted average yield (tax equivalent-adjusted basis) of 7.58% and 6.51%,
respectively. During the first nine months of 2006 and 2005, earning assets had
a weighted average yield of 7.39% and 6.23%, respectively. With approximately
65% of our total loans and leases tied to the prime rate, our asset yield has
benefited from recent increases in the prime rate. Between June 30, 2004 and
September 30, 2006, the Federal Open Market Committee has raised the target
federal funds rate by a total of 425 basis points, with the prime rate
increasing by the same magnitude.

Interest expense during the third quarter of 2006 was $20.1 million, an increase
of 58.6% over the $12.7 million expensed during the third quarter of 2005.
Interest expense during the first nine months of 2006 was $54.2 million, an
increase of 67.0% over the $32.5 million expensed during the first nine months
of 2005. The increase in interest expense is primarily attributable to the
increase in interest-bearing liabilities necessitated by the growth in assets
and a higher interest rate environment. During the third quarter of 2006,
interest-bearing liabilities averaged $1,683.9 million, $222.2 million higher
than average interest-bearing liabilities of $1,461.7 million during the third
quarter of 2005. Interest-bearing deposits were up $228.5 million, while FHLBI
advances decreased $13.9 million. During the first nine months of 2006,
interest-bearing liabilities averaged $1,639.3 million, $240.2 million higher
than average interest-bearing liabilities of $1,399.1 million during the same
time period in 2005. Interest-bearing deposits were up $233.5 million, while
FHLBI advances decreased $2.8 million. During the third quarter of 2006 and
2005, interest-bearing liabilities had a weighted average rate of 4.74% and
3.44%, respectively. During the first nine months of 2006 and 2005,
interest-bearing liabilities had a weighted average rate of 4.42% and 3.10%,
respectively. The higher weighted average cost of interest-bearing liabilities
is primarily due to the increase in market interest rates.


                                       27



                           MERCANTILE BANK CORPORATION

Net interest income during the third quarter of 2006 was $15.5 million, an
increase of 10.5% over the $14.1 million earned during the third quarter of
2005. Net interest income during the first nine months of 2006 was $46.3
million, an increase of 14.8% over the $40.3 million earned during the same time
period in 2005. The increase in net interest income is primarily due to the
growth in earning assets, which more than offset a decline in the net interest
margin. The net interest margin during the third quarter of 2006 was 3.34%,
compared to the 3.46% during the third quarter of 2005. During the first nine
months of 2006, the net interest margin was 3.44%, compared to 3.48% during the
same time period in 2005.

The following table sets forth certain information relating to our consolidated
average interest-earning assets and interest-bearing liabilities and reflects
the average yield on assets and average cost of liabilities for the third
quarter of 2006 and 2005. Such yields and costs are derived by dividing income
or expense by the average daily balance of assets or liabilities, respectively,
for the period presented. Tax-exempt securities interest income and yield have
been computed on a tax equivalent basis using a marginal tax rate of 35%.
Securities interest income was increased by $296,000 and $282,000 in the third
quarter of 2006 and 2005, respectively, for this adjustment.



                                                   Quarters ended September 30,
                                -----------------------------------------------------------------
                                              2006                              2005
                                -------------------------------   -------------------------------
                                  Average               Average     Average               Average
                                  Balance    Interest     Rate      Balance    Interest     Rate
                                ----------   --------   -------   ----------   --------   -------
                                                      (dollars in thousands)
                                                                        
ASSETS
   Loans and leases             $1,684,700    $33,261    7.83%    $1,460,792    $24,570    6.67%
   Securities                      191,160      2,631    5.51        177,539      2,395    5.40
   Federal funds sold                5,750         76    5.17          8,274         76    3.58
   Short-term investments              262          3    5.15            689          5    2.68
                                ----------    -------             ----------    -------
      Total interest-earning
         assets                  1,881,872     35,971    7.58      1,647,294     27,046    6.51

   Allowance for loan and
      lease losses                 (21,697)                          (19,343)
   Other assets                    124,024                           112,252
                                ----------                        ----------
      Total assets              $1,984,199                        $1,740,203
                                ==========                        ==========

LIABILITIES AND
   SHAREHOLDERS' EQUITY
   Interest-bearing deposits    $1,453,005    $17,268    4.72%    $1,224,483    $10,554    3.42%
   Short-term borrowings            71,652        707    3.91         64,970        475    2.90
   FHLB advances                   123,206      1,452    4.61        137,120      1,148    3.28
   Long-term borrowings             36,004        701    7.72         35,110        515    5.82
                                ----------    -------             ----------    -------
      Total interest-bearing
         liabilities             1,683,867     20,128    4.74      1,461,683     12,692    3.44

   Noninterest-bearing
     deposits                      116,609                           115,003
   Other liabilities                19,163                            12,977
   Shareholders' equity            164,560                           150,540
                                ----------                        ----------
      Total liabilities and
         shareholders' equity   $1,984,199                        $1,740,203
                                ==========    -------             ==========    -------
   Net interest income                        $15,843                           $14,354
                                              =======                           =======
   Net interest rate spread                              2.84%                             3.07%
                                                         ====                              ====
   Net interest rate spread
      on average assets                                  3.17%                             3.27%
                                                         ====                              ====
   Net interest margin on
      earning assets                                     3.34%                             3.46%
                                                         ====                              ====




                                       28



                           MERCANTILE BANK CORPORATION

Provisions to the allowance during the third quarter of 2006 were $1.4 million,
an increase of 50.8% over the $0.9 million that was expensed during the third
quarter of 2005. Provisions to the allowance during the first nine months of
2006 were $4.1 million, an increase of 61.7% over the $2.5 million that was
expensed during the same time period in 2005. The increase during both time
periods primarily reflects the higher volume of net loan and lease charge-offs.
Net loan and lease charge-offs of $0.9 million were recorded during the third
quarter of 2006, compared to net loan and lease charge-offs of $0.2 million
during the third quarter of 2005. During the first nine months of 2006, net loan
and lease charge-offs totaled $2.7 million, compared to net loan and lease
charge-offs of $0.8 million during the same time period in 2005. The allowance,
as a percentage of total loans outstanding, was 1.28% as of September 30, 2006,
compared to 1.31% at September 30, 2005.

In each accounting period, the allowance is adjusted to the amount believed
necessary to maintain the allowance at adequate levels. Through the loan review
and credit departments, we attempt to allocate specific portions of the
allowance based on specifically identifiable problem loans and leases. The
evaluation of the allowance is further based on, although not limited to,
consideration of the internally prepared Allowance Analysis, composition of the
loan and lease portfolio, third party analysis of the loan administration
processes and loan portfolio and general economic conditions. In addition, the
rapid growth of the loan and lease portfolio is taken into account.

The Allowance Analysis, used since the inception of our bank and completed
monthly, applies reserve allocation factors to outstanding loan and lease
balances to calculate an overall allowance dollar amount. For commercial loans
and leases, which continue to comprise a vast majority of our loan and lease
portfolio, reserve allocation factors are based upon the loan ratings as
determined by our loan rating paradigm that is administered by our loan review
function. For retail loans, reserve allocation factors are based upon the type
of credit. Adjustments for specific loan relationships, including impaired
loans, are made on a case-by-case basis. The reserve allocation factors are
based on the experience of senior management making similar loans in the same
community over almost 20 years. The Allowance Analysis is reviewed regularly by
senior management and the Board of Directors and is adjusted periodically based
upon identifiable trends and experience.

Noninterest income during the third quarter of 2006 was $1.36 million, an
increase of 2.4% over the $1.33 million earned during the third quarter of 2005.
Noninterest income during the first nine months of 2006 was $3.88 million, an
increase of 3.2% over the $3.76 million earned during the same time period in
2005. Service charge income on deposits and repurchase agreements decreased
$8,000 (2.2%) during the third quarter of 2006 when compared to the third
quarter of 2005, and declined $42,000 (4.0%) during the first nine months of
2006 when compared to the same time period during 2005, primarily reflecting an
increase in the earnings credit rate on noninterest-bearing checking accounts
which was only partially offset by an increase in new accounts opened during the
last twelve months. During both time periods, we recorded increased fee income
in virtually all other major fee income categories.


                                       29



                           MERCANTILE BANK CORPORATION

Noninterest expense during the third quarter of 2006 was $8.0 million, a
decrease of 3.5% from the $8.3 million expensed during the third quarter of
2005. Noninterest expense during the first nine months of 2006 was $24.1
million, an increase of 7.8% over the $22.3 million expensed during the same
time period in 2005. Employee salary and benefit expenses were $0.3 million
lower during the third quarter of 2006 than the level expensed during the third
quarter of 2005, but were $0.6 million higher during the first nine months of
2006 than the level expensed during the first nine months of 2005. The decline
in the quarter-over-quarter comparison and the increase in the
year-to-date-over-year-to-date comparison primarily reflect increased costs from
the hiring of additional staff and merit annual pay increases but lower
non-lender bonus program expenses. The level of full-time equivalent employees
increased from 263 at September 30, 2005 to 284 as of September 30, 2006. During
the third quarter of 2005 and the first nine months of 2005, we expensed $0.7
million and $1.9 million, respectively, for the non-lender bonus program. During
the third quarter of 2006 and the first nine months of 2006, no expense was
recorded for the non-lender bonus program, primarily reflecting management's
assessment of the likelihood of achieving a 15% growth in net income for all of
2006.

Occupancy, furniture and equipment costs increased $0.1 million during the third
quarter of 2006 over the level expensed during the third quarter of 2005, and
increased $1.0 million during the first nine months of 2006 over the level
expensed during the first nine months of 2005, primarily reflecting the opening
of our new main office during the second quarter of 2005 and the opening of our
new leased facilities in Lansing and Ann Arbor during the third quarter of 2005.
Other overhead costs decreased $0.1 million during the third quarter of 2006
over the level expensed during the third quarter of 2005, but increased $0.2
million during the first nine months of 2006 over the level expensed during the
first nine months of 2005. While virtually all major general and administrative
costs were up during each of the time periods, the lack of initial start-up
costs for the Lansing and Ann Arbor banking offices during the third quarter of
2006 which were present during the third quarter of 2005 more than offset the
increase in the other costs during that specific time period. Monitoring and
controlling noninterest costs, while at the same time providing high quality
service to customers, is a key component to our business strategy. While the
dollar volume of noninterest costs has generally consistently increased, the
rate of growth has been lower than the rate of increase in net interest income
and noninterest income.

Federal income tax expense was $2.3 million during the third quarter of 2006, an
increase of 23.4% over the $1.9 million expensed during the third quarter of
2005. Federal income tax expense was $6.8 million during the first nine months
of 2006, an increase of 15.0% over the $5.9 million expensed during the first
nine months of 2005. The increases during both time periods primarily results
from the increase in net income before federal income tax. Our effective tax
rate was approximately 30.9% during the third quarter of 2006 and the first nine
months of 2006, compared to approximately 30.6% during the third quarter of 2005
and the first nine months of 2005.


                                       30



                           MERCANTILE BANK CORPORATION

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Our primary market risk exposure is interest rate risk and, to a lesser extent,
liquidity risk. All of our transactions are denominated in U.S. dollars with no
specific foreign exchange exposure. We have only limited agricultural-related
loan assets and therefore have no significant exposure to changes in commodity
prices. Any impact that changes in foreign exchange rates and commodity prices
would have on interest rates are assumed to be insignificant. Interest rate risk
is the exposure of our financial condition to adverse movements in interest
rates. We derive our income primarily from the excess of interest collected on
our interest-earning assets over the interest paid on our interest-bearing
liabilities. The rates of interest we earn on our assets and owe on our
liabilities generally are established contractually for a period of time. Since
market interest rates change over time, we are exposed to lower profitability if
we cannot adapt to interest rate changes. Accepting interest rate risk can be an
important source of profitability and shareholder value; however, excessive
levels of interest rate risk could pose a significant threat to our earnings and
capital base. Accordingly, effective risk management that maintains interest
rate risk at prudent levels is essential to our safety and soundness.

Evaluating the exposure to changes in interest rates includes assessing both the
adequacy of the process used to control interest rate risk and the quantitative
level of exposure. Our interest rate risk management process seeks to ensure
that appropriate policies, procedures, management information systems and
internal controls are in place to maintain interest rate risk at prudent levels
with consistency and continuity. In evaluating the quantitative level of
interest rate risk we assess the existing and potential future effects of
changes in interest rates on our financial condition, including capital
adequacy, earnings, liquidity and asset quality.

We use two interest rate risk measurement techniques. The first, which is
commonly referred to as GAP analysis, measures the difference between the dollar
amounts of interest sensitive assets and liabilities that will be refinanced or
repriced during a given time period. A significant repricing gap could result in
a negative impact to our net interest margin during periods of changing market
interest rates. The following table depicts our GAP position as of September 30,
2006 (dollars in thousands):


                                       31


                           MERCANTILE BANK CORPORATION



                                           Within     Three to     One to       After
                                           Three       Twelve       Five         Five
                                           Months      Months       Years       Years       Total
                                          --------   ---------    --------    --------   ----------
                                                                          
Assets:
   Commercial loans and leases (1)        $871,667   $  67,884    $589,530    $ 45,183   $1,574,264
   Residential real estate loans            54,127       3,234      57,908      13,663      128,932
   Consumer loans                            1,278         650       4,557         587        7,072
   Investment securities (2)                 8,977       2,215      34,737     149,678      195,607
   Federal funds sold                       16,000           0           0           0       16,000
   Short-term investments                      176           0           0           0          176
   Allowance for loan and lease losses           0           0           0           0      (21,938)
   Other assets                                  0           0           0           0      126,721
                                          --------   ---------    --------    --------   ----------
      Total assets                         952,225      73,983     686,732     209,111    2,026,834
Liabilities:
   Interest-bearing checking                41,224           0           0           0       41,224
   Savings                                  78,239           0           0           0       78,239
   Money market accounts                     9,565           0           0           0        9,565
   Time deposits < $100,000                 32,171      51,483      35,838           0      119,492
   Time deposits $100,000 and over         299,726     640,620     310,568           0    1,250,914
   Short-term borrowings                    74,111           0           0           0       74,111
   FHLB advances                            35,000      65,000      15,000           0      115,000
   Long-term borrowings                     36,137           0           0           0       36,137
   Noninterest-bearing checking                  0           0           0           0      115,269
   Other liabilities                             0           0           0           0       19,335
                                          --------   ---------    --------    --------   ----------
      Total liabilities                    606,173     757,103     361,406           0    1,859,286
Shareholders' equity                             0           0           0           0      167,548
                                          --------   ---------    --------    --------   ----------
Total sources of funds                     606,173     757,103     361,406           0    2,026,834
                                          --------   ---------    --------    --------   ----------
Net asset (liability) GAP                 $346,052   $(683,120)   $325,326    $209,111
                                          ========   =========    ========    ========
Cumulative GAP                            $346,052   $(337,068)   $(11,742)   $197,369
                                          ========   =========    ========    ========
Percent of cumulative GAP to
   total assets                               17.1%      (16.6)%      (0.6)%       9.7%
                                          ========   =========    ========    ========


(1)  Floating rate loans that are currently at interest rate floors or ceilings
     are treated as fixed rate loans and are reflected using maturity date and
     not next repricing date.

(2)  Mortgage-backed securities are categorized by expected final maturities
     based upon prepayment trends as of September 30, 2006.

The second interest rate risk measurement we use is commonly referred to as net
interest income simulation analysis. We believe that this methodology provides a
more accurate measurement of interest rate risk than the GAP analysis, and
therefore, serves as our primary interest rate risk measurement technique. The
simulation model assesses the direction and magnitude of variations in net
interest income resulting from potential changes in market interest rates. Key
assumptions in the model include prepayment speeds on various loan and
investment assets; cash flows and maturities of interest-sensitive assets and
liabilities; and changes in market conditions impacting loan and deposit volume
and pricing. These assumptions are inherently uncertain, subject to fluctuation
and revision in a dynamic environment; therefore, the model cannot precisely
estimate net interest income or exactly predict the impact of higher or lower
interest rates on net interest income. Actual results will differ from simulated
results due to timing, magnitude, and frequency of interest rate changes and
changes in market conditions and the company's strategies, among other factors.


                                       32



                           MERCANTILE BANK CORPORATION

We conducted multiple simulations as of September 30, 2006, whereby it was
assumed that changes in market interest rates occurred ranging from up 200 basis
points to down 200 basis points in equal quarterly instalments over the next
twelve months. The following table reflects the suggested impact on our net
interest income over the next twelve months, which is well within our policy
parameters established to manage and monitor interest rate risk.



                                         Dollar Change In     Percent Change In
Interest Rate Scenario                 Net Interest Income   Net Interest Income
----------------------                 -------------------   -------------------
                                                       
Interest rates down 200 basis points       $(3,924,000)             (5.3)%
Interest rates down 100 basis points        (2,966,000)             (4.0)
No change in interest rates                 (2,183,000)             (2.9)
Interest rates up 100 basis points             133,000               0.2
Interest rates up 200 basis points           2,428,000               3.3


In addition to changes in interest rates, the level of future net interest
income is also dependent on a number of other variables, including: the growth,
composition and absolute levels of loans, deposits, and other earning assets and
interest-bearing liabilities; economic and competitive conditions; potential
changes in lending, investing and deposit gathering strategies; client
preferences; and other factors.

ITEM 4. CONTROLS AND PROCEDURES

As of September 30, 2006, an evaluation was performed under the supervision of
and with the participation of our management, including our Chief Executive
Officer and Chief Financial Officer, of the effectiveness of the design and
operation of our disclosure controls and procedures. Based on that evaluation,
our management, including our Chief Executive Officer and Chief Financial
Officer, concluded that our disclosure controls and procedures were effective as
of September 30, 2006. There have been no significant changes in our internal
controls over financial reporting during the quarter ended September 30, 2006
that have materially affected, or are reasonably likely to materially affect,
our internal controls over financial reporting.


                                       33




                           PART II - OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

From time to time, we may be involved in various legal proceedings that are
incidental to our business. In our opinion, we are not a party to any current
legal proceedings that are material to our financial condition, either
individually or in the aggregate.

ITEM 1A. RISK FACTORS

There have been no material changes in our risk factors from those previously
disclosed in our annual report on Form 10-K for the year ended December 31,
2005.

ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

Issuer Purchases of Equity Securities



                                                           (c) Total Number of Shares
                   (a) Total Number                           Purchased as Part of        (d) Maximum Number of Shares
                       of Shares      (b) Average Price   Publicly Announced Plans or    that May Yet Be Purchased Under
Period                 Purchased        Paid Per Share              Programs                  the Plans or Programs
------             ----------------   -----------------   ---------------------------   --------------------------------
                                                                            
July 1 - 31                 0                  N/A                     0                                0
August 1 - 31             218               $39.48                     0                                0
September 1 - 30            0                  N/A                     0                                0
                          ---               ------                   ---                              ---
Total                     218               $39.48                     0                                0
                          ===               ======                   ===                              ===


The shares shown in column (a) above as having been purchased were acquired from
one of our employees when they used shares of common stock that they already
owned to pay part of the exercise price when exercising stock options issued
under our employee stock option plans.

ITEM 3. DEFAULTS UPON SENIOR SECURITIES

Not applicable.

ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

Not applicable.

ITEM 5. OTHER INFORMATION

Not applicable.


                                       34




ITEM 6.  EXHIBITS



EXHIBIT NO.   EXHIBIT DESCRIPTION
-----------   -------------------
           
     3.1      Our Articles of Incorporation are incorporated by reference to
              Exhibit 3.1 of our Form 10-Q for the quarter ended June 30, 2004

     3.2      Our Amended and Restated Bylaws dated as of January 16, 2003 are
              incorporated by reference to Exhibit 3.2 of our Registration
              Statement on Form S-3 (Commission File No. 333-103376) that became
              effective on February 21, 2003

      31      Rule 13a-14(a) Certifications

    32.1      Section 1350 Chief Executive Officer Certification

    32.2      Section 1350 Chief Financial Officer Certification



                                       35




                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized, on November 8, 2006.

                                        MERCANTILE BANK CORPORATION


                                        By: /s/ Gerald R. Johnson, Jr.
                                            ------------------------------------
                                            Gerald R. Johnson, Jr.
                                            Chairman of the Board and Chief
                                            Executive Officer
                                            (Principal Executive Officer)


                                        By: /s/ Charles E. Christmas
                                            ------------------------------------
                                            Charles E. Christmas
                                            Senior Vice President, Chief
                                            Financial Officer and Treasurer
                                            (Principal Financial and
                                            Accounting Officer)


                                       36




                                  EXHIBIT INDEX



EXHIBIT NO.   EXHIBIT DESCRIPTION
-----------   -------------------
           
     3.1      Our Articles of Incorporation are incorporated by reference to
              Exhibit 3.1 of our Form 10-Q for the quarter ended June 30, 2004

     3.2      Our Amended and Restated Bylaws dated as of January 16, 2003 are
              incorporated by reference to Exhibit 3.2 of our Registration
              Statement on Form S-3 (Commission File No. 333-103376) that became
              effective on February 21, 2003

      31      Rule 13a-14(a) Certifications

    32.1      Section 1350 Chief Executive Officer Certification

    32.2      Section 1350 Chief Financial Officer Certification



                                       37