<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> UT
<LEGEND> This schedule contains summary financial information extracted from 
the Consolidated Balance Sheet and Statement of Consolidated Capitalization as 
of June 30, 1997 and the related Statements of Consolidated Income, Retained 
Earnings and Cash Flows for the six months ended June 30, 1997, and is qualified
in its entirety by reference to such financial statements. 
</LEGEND>
<CIK>      0000022606
<NAME>     Commonwealth Edison Company
<MULTIPLIER> 1,000
       
<S>                             <C>
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               JUN-30-1997
<BOOK-VALUE>                                  PER-BOOK
<TOTAL-NET-UTILITY-PLANT>                   17,036,688
<OTHER-PROPERTY-AND-INVEST>                  1,869,931
<TOTAL-CURRENT-ASSETS>                       1,407,729
<TOTAL-DEFERRED-CHARGES>                             0<F1>
<OTHER-ASSETS>                               3,009,199
<TOTAL-ASSETS>                              23,323,547
<COMMON>                                     2,677,830
<CAPITAL-SURPLUS-PAID-IN>                    2,207,553
<RETAINED-EARNINGS>                          1,084,199
<TOTAL-COMMON-STOCKHOLDERS-EQ>               5,969,582
<PREFERRED-MANDATORY>                          202,035
<PREFERRED>                                    507,103
<LONG-TERM-DEBT-NET>                         5,690,718<F2>
<SHORT-TERM-NOTES>                               7,750
<LONG-TERM-NOTES-PAYABLE>                            0<F2>
<COMMERCIAL-PAPER-OBLIGATIONS>                 256,000
<LONG-TERM-DEBT-CURRENT-PORT>                  531,612
<PREFERRED-STOCK-CURRENT>                       43,574
<CAPITAL-LEASE-OBLIGATIONS>                    522,746
<LEASES-CURRENT>                               136,067
<OTHER-ITEMS-CAPITAL-AND-LIAB>               9,456,360<F3>
<TOT-CAPITALIZATION-AND-LIAB>               23,323,547
<GROSS-OPERATING-REVENUE>                    3,399,142
<INCOME-TAX-EXPENSE>                            98,221
<OTHER-OPERATING-EXPENSES>                   2,907,320
<TOTAL-OPERATING-EXPENSES>                   3,007,661
<OPERATING-INCOME-LOSS>                        391,481
<OTHER-INCOME-NET>                            (15,238)<F4><F5>
<INCOME-BEFORE-INTEREST-EXPEN>                 378,363
<TOTAL-INTEREST-EXPENSE>                       249,721
<NET-INCOME>                                   128,642
<PREFERRED-STOCK-DIVIDENDS>                     31,012
<EARNINGS-AVAILABLE-FOR-COMM>                   97,630
<COMMON-STOCK-DIVIDENDS>                       171,381
<TOTAL-INTEREST-ON-BONDS>                            0<F6>
<CASH-FLOW-OPERATIONS>                         856,207
<EPS-PRIMARY>                                     0.46
<EPS-DILUTED>                                        0
<FN>

<F1> This item is not disclosed as a separate line item on the Consolidated 
     Balance Sheet.

<F2> $826,557 thousand of notes and long-term note payable to bank is included
     in LONG-TERM-DEBT-NET.

<F3> Includes $350,000 thousand of company-obligated mandatorily redeemable 
     preferred securities of subsidiary trusts.

<F4> A tax benefit of $2,120 thousand related to nonoperating activities is 
     included in INCOME-TAX-EXPENSE.

<F5> Includes $14,076 thousand of provision for preferred securities dividends 
     of subsidiary trusts.

<F6> This item is not disclosed as a separate line item on the Statement of 
     Consolidated Income. 

</FN>
        

</TABLE>