A low voltage plasma ion plating (LVIP) system has been set up based on the actions of plasma with the coating vaporant during thin film deposition. The conventional optical thin film materials, such as sulphide, oxides and multilayer thin film devices have been studied using this system. The spectral transmittance, absorption, sacttering and the packing density of the films have been measured and analyzed. Experiment results show that LVIP can improve significantly the optical and mechanical performance of the thin films deposited.