<TABLE> <S> <C>

<ARTICLE>                     UT

<LEGEND>
This schedule contains summary financial information extracted from the December
31, 1999 Financial Statements included in Alliant Energy Corporation's Form 10-K
and is qualified in its entirety by reference to such Financial Statements.
</LEGEND>

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

<S>                                                         <C>
<PERIOD-TYPE>                                      12-MOS
<FISCAL-YEAR-END>                                              DEC-31-1999
<PERIOD-START>                                                 JAN-01-1999
<PERIOD-END>                                                   DEC-31-1999
<BOOK-VALUE>                                                      PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                                        3,128,276
<OTHER-PROPERTY-AND-INVEST>                                      2,010,727
<TOTAL-CURRENT-ASSETS>                                             485,986
<TOTAL-DEFERRED-CHARGES>                                           187,084
<OTHER-ASSETS>                                                     263,610
<TOTAL-ASSETS>                                                   6,075,683
<COMMON>                                                               790
<CAPITAL-SURPLUS-PAID-IN>                                          942,408
<RETAINED-EARNINGS>                                              1,212,367 <F1>
<TOTAL-COMMON-STOCKHOLDERS-EQ>                                   2,155,565
<PREFERRED-MANDATORY>                                               24,536
<PREFERRED>                                                         89,102
<LONG-TERM-DEBT-NET>                                             1,486,765
<SHORT-TERM-NOTES>                                                  50,046
<LONG-TERM-NOTES-PAYABLE>                                           55,100
<COMMERCIAL-PAPER-OBLIGATIONS>                                     374,673
<LONG-TERM-DEBT-CURRENT-PORT>                                       54,795
<PREFERRED-STOCK-CURRENT>                                                0
<CAPITAL-LEASE-OBLIGATIONS>                                         26,041
<LEASES-CURRENT>                                                    13,321
<OTHER-ITEMS-CAPITAL-AND-LIAB>                                   1,745,739
<TOT-CAPITALIZATION-AND-LIAB>                                    6,075,683
<GROSS-OPERATING-REVENUE>                                        2,197,963
<INCOME-TAX-EXPENSE>                                               120,486 <F2>
<OTHER-OPERATING-EXPENSES>                                       1,821,428
<TOTAL-OPERATING-EXPENSES>                                       1,821,428 <F2>
<OPERATING-INCOME-LOSS>                                            376,535
<OTHER-INCOME-NET>                                                  83,467
<INCOME-BEFORE-INTEREST-EXPEN>                                     460,002
<TOTAL-INTEREST-EXPENSE>                                           136,229
<NET-INCOME>                                                       203,287
<PREFERRED-STOCK-DIVIDENDS>                                          6,706
<EARNINGS-AVAILABLE-FOR-COMM>                                      196,581
<COMMON-STOCK-DIVIDENDS>                                           156,489
<TOTAL-INTEREST-ON-BONDS>                                          112,196
<CASH-FLOW-OPERATIONS>                                             423,129
<EPS-BASIC>                                                           2.51
<EPS-DILUTED>                                                         2.51


<FN>
<F1> Includes $634,903 of Accumulated Other Comprehensive Income.

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

</TABLE>