In this paper, we have reported on improved titanyl phthalocyanine (TiOPc) thin film transistor (TFT) performance utilizing an alpha,alpha '-dihexylsexithiophene (DH-alpha 6T) submonolayer. By the detailed XRD and AFM analysis, highly ordering alpha-TiOPc thin films could be deposited on SiO2/Si substrates modified by a DH-alpha 6T submonolayer. Organic TFT with a TiOPc/ DH-alpha 6T bilayer as active layers realized high mobility of 2.45 x 10(-1) cm(2) /V s, which is about 100times greater than that of TiOPc single layer device.