Registration No. 333-___________
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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
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                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           THE SECURITIES ACT OF 1933
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                           ALLIANT ENERGY CORPORATION
             (Exact name of registrant as specified in its charter)

            Wisconsin                                        39-1380265
  (State or other jurisdiction of                        (I.R.S. Employer
  incorporation or organization)                         Identification No.)

    4902 North Biltmore Lane
        Madison, Wisconsin                                     53718-2132
(Address of principal executive offices)                       (Zip Code)

              Alliant Energy Corporation 2002 Equity Incentive Plan
                            (Full title of the plan)

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                 F.J. Buri                                     Copy to:
            Corporate Secretary
        Alliant Energy Corporation                     Benjamin F. Garmer, III
         4902 North Biltmore Lane                          Foley & Lardner
       Madison, Wisconsin 53718-2132                  777 East Wisconsin Avenue
              (608) 458-3311                          Milwaukee, Wisconsin 53202
   (Name, address and telephone number,                     (414) 271-2400
including area code, of agent for service)
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                         CALCULATION OF REGISTRATION FEE
------------------------ -------------------------- --------------------- ---------------------- -----------------
       Title of                   Amount              Proposed Maximum      Proposed Maximum
   Securities to be                to be               Offering Price      Aggregate Offering       Amount of
      Registered                Registered               Per Share                Price          Registration Fee
------------------------ -------------------------- --------------------- ---------------------- -----------------
                                                                                        
Common Stock,                4,000,000 shares            $27.92(1)           $111,680,000(1)        $10,274.56
$.01 par value

Common Share                 4,000,000 rights               (2)                    (2)                 (2)
Purchase Rights
------------------------ -------------------------- --------------------- ---------------------- -----------------

(1) Estimated pursuant to Rule 457(c) and (h) under the Securities Act of 1933
    solely for the purpose of calculating the registration fee based on the
    average of the high and low prices for Alliant Energy Corporation Common
    Stock on the New York Stock Exchange Composite Tape on May 8, 2002.

(2) The value attributable to the Common Share Purchase Rights is reflected in
    the market price of the Common Stock to which the Rights are attached.


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                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

       The document or documents containing the information specified in Part I
are not required to be filed with the Securities and Exchange Commission (the
"Commission") as part of this Registration Statement on Form S-8.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

       The following documents filed with the Commission by Alliant Energy
Corporation (the "Company") are hereby incorporated herein by reference:

       1. The Company's Annual Report on Form 10-K for the fiscal year ended
December 31, 2001.

       2. The Company's Quarterly Report on Form 10-Q for the quarter ended
March 31, 2002.

       3. The description of the Company's Common Stock contained in Item 4 of
the Company's Registration Statement on Form 8-B, dated April 1, 1988, including
any amendment or report filed for the purpose of updating such description.

       4. The description of the Company's Common Share Purchase Rights
contained in Item 1 of the Company's Registration Statement on Form 8-A, dated
January 20, 1999, including any amendment or report filed for the purpose of
updating such description.

       All documents subsequently filed by the Company pursuant to Sections
13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended,
after the date of filing of this Registration Statement and prior to such time
as the Company files a post-effective amendment to this Registration Statement
which indicates that all securities offered hereby have been sold or which
deregisters all securities then remaining unsold shall be deemed to be
incorporated by reference in this Registration Statement and to be a part hereof
from the date of filing of such documents.

Item 4.  Description of Securities.

       Not applicable.


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Item 5.  Interests of Named Experts and Counsel.

       None.

Item 6.  Indemnification of Directors and Officers.

       Pursuant to the Wisconsin Business Corporation Law and the Company's
By-laws, as amended, directors and officers of the Company are entitled to
mandatory indemnification from the Company against certain liabilities and
expenses (i) to the extent such officers or directors are successful in the
defense of a proceeding and (ii) in proceedings in which the director or officer
is not successful in the defense thereof, unless it is determined that the
director or officer breached or failed to perform his or her duties to the
Company and such breach or failure constituted: (a) a willful failure to deal
fairly with the Company or its shareowners in connection with a matter in which
the director or officer had a material conflict of interest; (b) a violation of
the criminal law, unless the director or officer had reasonable cause to believe
his or her conduct was lawful or had no reasonable cause to believe his or her
conduct was unlawful; (c) a transaction from which the director or officer
derived an improper personal profit; or (d) willful misconduct. The Wisconsin
Business Corporation Law specifically states that it is the policy of Wisconsin
to require or permit indemnification in connection with a proceeding involving
securities regulation, as described therein, to the extent required or permitted
as described above. Additionally, under the Wisconsin Business Corporation Law,
directors of the Company are not subject to personal liability to the Company,
its shareowners or any person asserting rights on behalf thereof for certain
breaches or failures to perform any duty resulting solely from their status as
directors except in circumstances paralleling those in subparagraphs (a) through
(d) outlined above.

       The indemnification provided by the Wisconsin Business Corporation Law
and the Company's By-laws is not exclusive of any other rights to which a
director or officer may be entitled. The general effect of the foregoing
provisions may be to reduce the circumstances in which an officer or director
may be required to bear the economic burden of the foregoing liabilities and
expenses.

       The Company maintains a liability insurance policy for its directors and
officers as permitted by Wisconsin law which may extend to, among other things,
liability arising under the Securities Act of 1933, as amended.

Item 7.  Exemption from Registration Claimed.

       Not applicable.

Item 8.  Exhibits.

       The exhibits filed herewith or incorporated herein by reference are set
forth in the attached Exhibit Index.



                                      -3-


Item 9.  Undertakings.

       (a) The undersigned Registrant hereby undertakes:

       (1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this Registration Statement:

              (i) To include any prospectus required by Section 10(a)(3) of the
       Securities Act of 1933;

              (ii) To reflect in the prospectus any facts or events arising
       after the effective date of the Registration Statement (or the most
       recent post-effective amendment thereof) which, individually or in the
       aggregate, represent a fundamental change in the information set forth in
       the Registration Statement;

              (iii) To include any material information with respect to the plan
       of distribution not previously disclosed in the Registration Statement or
       any material change to such information in the Registration Statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the
information required to be included in a post-effective amendment by those
paragraphs is contained in periodic reports filed with or furnished to the
Commission by the Registrant pursuant to Section 13 or Section 15(d) of the
Securities Exchange Act of 1934 that are incorporated by reference in the
Registration Statement.

       (2) That, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

       (3) To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

       (b) The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 that is incorporated by reference in this
Registration Statement shall be deemed to be a new registration statement
relating to the securities offered herein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

       (c) Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the Registrant pursuant to the foregoing provisions, or otherwise,
the Registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the


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Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.





                                      -5-


                                   SIGNATURES

       Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Madison, State of Wisconsin, on this 15th day of May,
2002.

                                            ALLIANT ENERGY CORPORATION



                                            By: /s/ Erroll B. Davis, Jr.
                                                --------------------------------
                                                Erroll B. Davis, Jr.
                                                Chairman, President and
                                                  Chief Executive Officer

       Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.

       Signature                   Title                               Date

/s/ Erroll B. Davis        Chairman, President and Chief           May 15, 2002
-----------------------    Executive Officer and Director
Erroll B. Davis, Jr.       (Principal Executive Officer)

/s/ Thomas M. Walker       Executive Vice President and Chief      May 15, 2002
-----------------------    Financial Officer (Principal
Thomas M. Walker           Financial Officer)

/s/ John E. Kratchmer      Corporate Controller and Chief          May 15, 2002
-----------------------    Accounting Officer (Principal
John E. Kratchmer          Accounting Officer)

        *                        Director                          May 15, 2002
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Alan B. Arends

        *                        Director                          May 15, 2002
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Jack B. Evans

        *                        Director                          May 15, 2002
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Joyce L. Hanes

                                       S-1


        *                        Director                          May 15, 2002
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Lee Liu

        *                        Director                          May 15, 2002
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Katharine C. Lyall

        *                        Director                          May 15, 2002
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Singleton B. McAllister

        *                        Director                          May 15, 2002
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David A. Perdue

        *                        Director                          May 15, 2002
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Judith D. Pyle

        *                        Director                          May 15, 2002
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Robert W. Schlutz

        *                        Director                          May 15, 2002
-----------------------
Wayne H. Stoppelmoor

        *                        Director                          May 15, 2002
---------------------------
Anthony R. Weiler

*By:  /s/ Erroll B. Davis, Jr.
      ------------------------
      Erroll B. Davis, Jr.
      Attorney-in-Fact


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                                  EXHIBIT INDEX

Exhibit
Number                          Exhibit Description

(4.1)     Restated Articles of Incorporation of Alliant Energy Corporation, as
          amended (incorporated by reference to Exhibit 3.2 to the Company's
          Quarterly Report on Form 10-Q for the quarter ended June 30, 1999).

(4.2)     Alliant Energy Corporation 2002 Equity Incentive Plan.

(4.3)     Form of Nonqualified Stock Option Agreement for use in connection with
          the Alliant Energy Corporation 2002 Equity Incentive Plan.

(4.4)     Rights Agreement, dated as of January 20, 1999, between Alliant Energy
          Corporation and U.S. Bank National Association (formerly known as
          Firstar Bank, N. A.) (incorporated by reference to Exhibit 4.1 to the
          Company's Registration Statement on Form 8-A, dated January 20, 1999
          (File No. 1-9894)).

(5)       Opinion of Foley & Lardner.

(23.1)    Consent of Arthur Andersen LLP.

(23.2)    Consent of Foley & Lardner (contained in Exhibit (5)).

(24)      Powers of Attorney.


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