<TABLE> <S> <C>
<ARTICLE> UT
<CIK>0000081027
<NAME> PUBLIC SERVICE COMPANY OF OKLAHOMA
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-1999
<PERIOD-END> JUN-30-2000
<BOOK-VALUE> PER-BOOK
<TOTAL-NET-UTILITY-PLANT> 1,392,450
<OTHER-PROPERTY-AND-INVEST> 43,814
<TOTAL-CURRENT-ASSETS> 133,740
<TOTAL-DEFERRED-CHARGES> 10,494
<OTHER-ASSETS> 0
<TOTAL-ASSETS> 1,580,498
<COMMON> 157,230
<CAPITAL-SURPLUS-PAID-IN> 180,000
<RETAINED-EARNINGS> 120,995
<TOTAL-COMMON-STOCKHOLDERS-EQ> 458,225
0
5,283
<LONG-TERM-DEBT-NET> 419,669
<SHORT-TERM-NOTES> 148,859
<LONG-TERM-NOTES-PAYABLE> 0
<COMMERCIAL-PAPER-OBLIGATIONS> 0
<LONG-TERM-DEBT-CURRENT-PORT> 30,000
0
<CAPITAL-LEASE-OBLIGATIONS> 0
<LEASES-CURRENT> 0
<OTHER-ITEMS-CAPITAL-AND-LIAB> 518,462
<TOT-CAPITALIZATION-AND-LIAB> 1,580,498
<GROSS-OPERATING-REVENUE> 370,501
<INCOME-TAX-EXPENSE> 8,023
<OTHER-OPERATING-EXPENSES> 327,116
<TOTAL-OPERATING-EXPENSES> 335,139
<OPERATING-INCOME-LOSS> 35,362
<OTHER-INCOME-NET> 716
<INCOME-BEFORE-INTEREST-EXPEN> 36,078
<TOTAL-INTEREST-EXPENSE> 20,213
<NET-INCOME> 15,865
106
<EARNINGS-AVAILABLE-FOR-COMM> 15,759
<COMMON-STOCK-DIVIDENDS> 34,000
<TOTAL-INTEREST-ON-BONDS> 11,987
<CASH-FLOW-OPERATIONS> 59,009
<EPS-BASIC> 0.00<F1>
<EPS-DILUTED> 0.00<F1>
<FN>
<F1> ALL COMMON STOCK OWNED BY THE PRENT COMPANY; NO EPS REQUIRED
</FN>
</TABLE>
