<ARTICLE>  UT
<CIK>  0000081027
<NAME>  PUBLIC SERVICE COMPANY OF OKLAHOMA
<SUBSIDIARY>
<NUMBER> 004
<NAME>  PUBLIC SERVICE COMPANY OF OKLAHOMA
<MULTIPLIER> 1,000

                                    
<PERIOD-TYPE>                          12-MOS
<FISCAL-YEAR-END>                             DEC-31-1999
<PERIOD-END>                                  DEC-31-1999
<BOOK-VALUE>                                     PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                       1,345,450
<OTHER-PROPERTY-AND-INVEST>                        18,644
<TOTAL-CURRENT-ASSETS>                            123,375
<TOTAL-DEFERRED-CHARGES>                            4,520
<OTHER-ASSETS>                                     51,882
<TOTAL-ASSETS>                                  1,543,871
<COMMON>                                          157,230
<CAPITAL-SURPLUS-PAID-IN>                         180,000
<RETAINED-EARNINGS>                               142,018
<TOTAL-COMMON-STOCKHOLDERS-EQ>                    479,248
<PREFERRED-MANDATORY>                                   0
<PREFERRED>                                         5,286
<LONG-TERM-DEBT-NET>                              419,516
<SHORT-TERM-NOTES>                                 79,169
<LONG-TERM-NOTES-PAYABLE>                          20,000
<COMMERCIAL-PAPER-OBLIGATIONS>                          0
<LONG-TERM-DEBT-CURRENT-PORT>                      20,000
<PREFERRED-STOCK-CURRENT>                               0
<CAPITAL-LEASE-OBLIGATIONS>                             0
<LEASES-CURRENT>                                        0
<OTHER-ITEMS-CAPITAL-AND-LIAB>                    520,652
<TOT-CAPITALIZATION-AND-LIAB>                   1,543,871
<GROSS-OPERATING-REVENUE>                         749,390
<INCOME-TAX-EXPENSE>                               34,184
<OTHER-OPERATING-EXPENSES>                        615,396
<TOTAL-OPERATING-EXPENSES>                        649,580
<OPERATING-INCOME-LOSS>                            99,810
<OTHER-INCOME-NET>                                    946
<INCOME-BEFORE-INTEREST-EXPEN>                    100,756
<TOTAL-INTEREST-EXPENSE>                           38,151
<NET-INCOME>                                       62,605
<PREFERRED-STOCK-DIVIDENDS>                           213
<EARNINGS-AVAILABLE-FOR-COMM>                      62,392
<COMMON-STOCK-DIVIDENDS>                           65,000
<TOTAL-INTEREST-ON-BONDS>                          24,098
<CASH-FLOW-OPERATIONS>                            112,592
<EPS-BASIC>                                             0
<EPS-DILUTED>                                           0