From plasma polymerization of nickel carbonyl with or without methane, metallic nickel powder, metal-like nickel film, nickel-containing DLC film and nickel-containing hydrocarbon polymer film were prepared. The results for metal-like nickel and nickel-containing DLC films deposited on monocrystalline silicon friction blocks suggest that the tribological properties of the films are related to the film composition, structure and friction conditions. High nickel content DLC film displays a stable friction coefficient of 0.12 with a small pulse of 0.01. In the ball-on-disc wear test, the wear resistance of the film and the coupler steel ball increased by factors of 74.6 and 316.7, respectively. The improvement in tribological behavior results from the insertion of nickel into the film, which reduces the intrinsic brittleness and internal stress of DLC firm, and plays the role of composite lubrication with DLC.