In this study, p-type thin film transistors consisting of CuO channels were fabricated by sol-gel process, with copper (II) acetate monohydrate precursors. At 500℃, the deposited films were fully converted into monoclinic phase CuO. The fabricated CuO thin film transistors deliver field effect mobility in saturation regime of 0.015㎠/Vs, and I_on/I_off of ~10³. The degradation of the performance of the fabricated CuO thin film transistor caused by the exposure to air has been studied.