Different content of nanoZn/UHMWPE composites were prepared by a hotpressing molding method.The tribological performance of UHMWPE and its composites under dry friction were evaluated on fretting friction and wear tester.The fractured surfaces were analyzed by field emission scanning electron microscope.The worn surfaces of polymers and steel balls were studied by scanning electron microscope to further investigate the wear mechanism.The results show that the friction coefficient and specific wear rate are firstly decreased and then increased with increasing contents of nanoZn.The lowest friction coefficient and specific wear rate are obtained when the mass content of nanoZn is 1%,meanwhile,the uniform and continuous transfer film is formed on the steel ball surface.The main wear mechanism of the composites is adhesion and abrasion.Therefore,nanoZn can significantly improve the fretting wear properties of composites,and 10%Zn/UHMWPE composites have the best fretting wear performance.