Exhibit 21 PECO Energy Company Subsidiaries and State of Incorporation At December 31, 1995 PECO Energy Power Company - Incorporated in Pennsylvania Susquehanna Power Company - Incorporated in Maryland PECO Energy Capital Corp. - Incorporated in Delaware PECO Gas Supply Company - Incorporated in Pennsylvania PECO Wireless, Inc. - Incorporated in Pennsylvania The Proprietors of the Susquehanna Canal (Inactive)- Incorporated in Maryland Susquehanna Electric Company - Incorporated in Maryland Eastern Pennsylvania Development Company - Incorporated in Pennsylvania Adwin (Schuylkill) Cogeneration, Inc. - Incorporated in Pennsylvania Adwin Equipment Company - Incorporated in Pennsylvania Adwin Realty Company - Incorporated in Pennsylvania Adwin Investment Company - Incorporated in Delaware Buttonwood Associates, Inc. - Incorporated in Delaware Energy Performance Services, Inc. - Incorporated In Pennsylvania Eastern Pennsylvania Exploration Company - Incorporated in Pennsylvania