High-Tc superconductor thick films of YBa2Cu$chi$O7-y (X=3, 3.5, 4) of which thickness varies from 100 $mu extrm{m}$ to 200 $mu extrm{m}$ were successfully prepared by plasma spraying method, and the characteristics of thick film depending on copper content and heat treatment conditions were investigated. Regardless of heat-treated temperature, the specimens with X=3 were composed of YBa2Cu$chi$O7-y, Y2BaCuO5 and BaCuO3 phases. The specimens with X=4, however, were composed of YBa2Cu$chi$O7-y phase at all heat treatment conditions. The specimens with X=4 composition showed the best superconducting characteristics after heat treatment at 925$^{circ}C$, and the superconducting transition temperature with zero resistivity (Tc,zero) was 87K. The thick film lost superconductivity when the specimens were heat-treated at 950$^{circ}C$ because of interdiffusion between superconductor elements and bond coating elements and Y2BaCuO5 phase was found was found to be main phase at the interface.