1 BOK FINANCIAL CORPORATION EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT BANKING SUBSIDIARIES -------------------- Bank of Oklahoma, National Association Bank of Arkansas, National Association Bank of Texas, National Association Bank of Albuquerque, National Association OTHER SUBSIDIARIES OF BOK FINANCIAL CORPORATION ----------------------------------------------- BOSC, Inc. BOK Capital Services Corporation KCI Leasing Partners I, an Oklahoma Limited Partnership KCI Leasing Partners II, an Oklahoma Limited Partnership KCI Leasing Partners III, an Oklahoma Limited Partnership KCI Leasing Partners IV, an Oklahoma Limited Partnership Park Cities Bancshares, Inc. Park Cities Corporation Sabre 1996 Partnership, an Oklahoma Limited Partnership SUBSIDIARIES OF BANK OF OKLAHOMA, N.A. -------------------------------------- Affiliated BancServices, Inc. Affiliated Financial Holding Company Affiliated Financial Insurance Agency, Inc. Affiliated Financial Life Insurance Company BancOklahoma Agri-Service Corporation BancOklahoma Mortgage Corporation BOK Delaware, Inc. BOK Real Estate Trust CVV Management, Inc. CVV Partnership, an Oklahoma General Partnership Cottonwood Valley Ventures, Inc. Investment Concepts, Inc. Pacesetter Leasing Company Southwest Trust Company Steven L. Smith Corporation 115 E. Fifth Corp. SUBSIDIARIES OF BANK OF TEXAS, N.A. ----------------------------------- Bank of Texas Trust Company, National Association All subsidiaries are incorporated in Oklahoma, with the exception of Bank of Oklahoma, National Association, Bank of Arkansas, National Association, Bank of Texas, National Association, Bank of Texas Trust Company, National Association, and Bank of Albuquerque, National Association, which are chartered by the United States of America; Affiliated Financial Life Insurance Company,which is incorporated in Arizona; Park Cities Bancshares, Inc. and BOK Real Estate Trust which are incorporated in Texas; BOK Delaware, Inc., which is incorporated in Delaware; and Park Cities Corporation, which is incorporated in Nevada.