Bi-layered thermally grown oxide(TGO) layer plays a major role in the spallation of Y2 O3 stabilized ZrO2(YSZ) layer form the bond coat in the thermal barrier coating(TBC) systems during oxidation. On the other hand, bi-layered TGO formation and growth in the TBC systems with nanostructured YSZ have not been deeply investigated during cyclic oxidation. Hence, Inconel 738/NiCrAlY/normal YSZ and Inconel 738/NiCrAlY/nano YSZ systems were pre-oxidized at 1000 °C and then subjected to cyclic oxidation at 1150 °C. According to microstructural observations, nanostructured YSZ layer over the bond coat should have less micro-cracks and pinholes, due to the compactness of the nanostructure and the presence of nano zones that resulted in lower O infiltration into the nanothermal barrier coating system, formation of thinner and nearly continuous mono-layered thermally grown oxide on the bond coat during pre-oxidation, lower spinels formation at the Al2 O3 /YSZ interface and finally, reduction of bi-layered thermally grown oxide thickness during cyclic oxidation. It was found that pre-heat treatment and particularly coating microstructure could influence microstructural evolution(bi-layered TGO thickness) and durability of thermal barrier coating systems during cyclic oxidation. Bi-layered thermally grown oxide (TGO) layer plays a major role in the spallation of Y2 O3 stabilized ZrO2 (YSZ) layer form the bond coat in the thermal barrier coating (TBC) systems during oxidation. On the other hand, bi-layered TGO formation and growth in the TBC systems with nanostructured YSZ have not been deeply investigated during cyclic oxidation. Therefore, Inconel 738 / NiCrAlY / normal YSZ and Inconel 738 / NiCrAlY / nano YSZ systems were pre-oxidized at 1000 ° C and then subjected to cyclic oxidation at 1150 ° C. According to microstructural observations, the nanostructured YSZ layer over the bond coat should have less micro-cracks and pinholes, due to the compactness of the nanostructure and the presence of nano zones that resulted in lower O infiltration into the nanothermal barrier coating system, formation of thinner and nearly continuous mono-layered thermally grown oxide on the bond coat during pre-oxidation, lower spinels formation at the Al 2 O 3 / YSZ interface and finally, reduction of bi-layered thermally grown oxide thickness during cyclic oxidation. It was found that pre-heat treatment and particularly coating microstructure could influence microstructural evolution (bi-layered TGO thickness) and durability of thermal barrier coating systems during cyclic oxidation.