Abstract: Nanometer copper sulfide/polydicyclopentadiene (nano-CuS/PDCPD) composites were successfully prepared by the reaction injecting molding, using tungsten complex as the main catalyst, diethyl aluminium chloride (Et₂AlCl) as the cocatalyst, and surface modified CuS nanopowders as the additive. The structure, dispersion of the fillers, worn surface, mechanical properties and friction and wear performance of the as-obtained CuS nanopowders and nano-CuS/PDCPD composities were characterized and tested by many technologies, such as FTIR, SEM, TEM, 3D morphology meter, and high-temperature atmosphere friction/wear tester. The results indicate that the mechanical property and friction and wear performance of nano-CuS/PDCPD composities are significantly enhanced compared to that of pristine PDCPD when surface modified CuS nanopowders are used in low addition range, and the comprehensive properties achieve their optimum with CuS mass fraction of 1%.The most increased values of impact strength, tensile strength, and bending strength are 13.2%, 22.0% and 13.8%, respectively. The wear mass and friction coefficient decrease 31% and 36%, respectively. The well interface compatibility between the particle/matrix interfaces plays an important role for the improved mechanical and tribological properties of nano-CuS/PDCPD composities in low CuS loadings.