<ARTICLE>                                      UT
<LEGEND>
This  schedule  contains  summary  financial   information  extracted  from  the
September 30, 1999 Financial Statements included in Alliant Energy Corporation's
Form 10-Q and is  qualified  in its  entirety  by  reference  to such  Financial
Statements.
</LEGEND>

<CIK>     0000352541
<NAME>    ALLIANT ENERGY CORPORATION
<MULTIPLIER>     1,000


                                             
<PERIOD-TYPE>                                   9-MOS
<FISCAL-YEAR-END>                                          DEC-31-1999
<PERIOD-START>                                             JAN-01-1999
<PERIOD-END>                                               SEP-30-1999
<BOOK-VALUE>                                                  PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                                    3,090,597
<OTHER-PROPERTY-AND-INVEST>                                  1,652,863
<TOTAL-CURRENT-ASSETS>                                         419,262
<TOTAL-DEFERRED-CHARGES>                                       165,809
<OTHER-ASSETS>                                                 268,714
<TOTAL-ASSETS>                                               5,597,245
<COMMON>                                                           787
<CAPITAL-SURPLUS-PAID-IN>                                      934,373
<RETAINED-EARNINGS>                                          1,047,660 <F1>
<TOTAL-COMMON-STOCKHOLDERS-EQ>                               1,982,820
<PREFERRED-MANDATORY>                                           24,502
<PREFERRED>                                                     89,102
<LONG-TERM-DEBT-NET>                                         1,569,531
<SHORT-TERM-NOTES>                                                  17
<LONG-TERM-NOTES-PAYABLE>                                       56,975
<COMMERCIAL-PAPER-OBLIGATIONS>                                 146,500
<LONG-TERM-DEBT-CURRENT-PORT>                                   53,679
<PREFERRED-STOCK-CURRENT>                                            0
<CAPITAL-LEASE-OBLIGATIONS>                                     27,590
<LEASES-CURRENT>                                                12,410
<OTHER-ITEMS-CAPITAL-AND-LIAB>                               1,634,119
<TOT-CAPITALIZATION-AND-LIAB>                                5,597,245
<GROSS-OPERATING-REVENUE>                                    1,631,305
<INCOME-TAX-EXPENSE>                                            91,623 <F2>
<OTHER-OPERATING-EXPENSES>                                   1,347,259
<TOTAL-OPERATING-EXPENSES>                                   1,347,259 <F2>
<OPERATING-INCOME-LOSS>                                        284,046
<OTHER-INCOME-NET>                                              64,737
<INCOME-BEFORE-INTEREST-EXPEN>                                 348,783
<TOTAL-INTEREST-EXPENSE>                                       100,347
<NET-INCOME>                                                   156,813
<PREFERRED-STOCK-DIVIDENDS>                                      5,029
<EARNINGS-AVAILABLE-FOR-COMM>                                  151,784
<COMMON-STOCK-DIVIDENDS>                                       117,121
<TOTAL-INTEREST-ON-BONDS>                                       90,966
<CASH-FLOW-OPERATIONS>                                         366,759
<EPS-BASIC>                                                     1.94
<EPS-DILUTED>                                                     1.94

<FN>
<F1> Includes $475,625 of Accumulated Other Comprehensive Income.

<F2> Income tax expense is not included in Operating Expense in the Consolidated
     Statements of Income.
</FN>