In thermal barrier coating (TBC) system, thermally grown oxide (TGO) forms at the interface between the top-coat and bond-coat during service. Delamination or spallation at the interface can be occurred by the TGO formation and growth. Therefore, Modifications of the bond-coat materials are one means to inhibit the TGO formation and to improve the bonding strength of TBCs. In this study, morphologies of TGO were controlled by using Ce and Si addition to conventional CoNiCrAlY bond-coat material. As a result, when the TBCs with Ce added bond-coat materials were aged at 1373K for 100 hours, morphologies of TGO were changed drastically. It is expected that the morphologies can improve bonding strength of TBCs. We carried out to evaluate the bonding strength by using four-point bending tests. As a result, TBC coated with Ce added bond-coat materials indicated excellent bonding strength.