Abstract: NBR/Fe3O4 composites and NBR/SrO.6Fe2O3 composites were prepared by blending. The friction coefficient and wear resistance were investigated by using UMT-2MT-friction and wear tester and surface profiler. The microstructures of the composites were observed using a scanning electronic microscopy (SEM) and the distribution of nano-Fe3O4 particles was observed by an energy dispersive spectrometer (EDS). The results showed that the anti-wear properties of NBR composites were improved using two kinds of nano-particles as fillers. And the tribological properties of NBR/ Fe3O4 composites were better than that of NBR/SrO.6Fe2O3 composites. The optimal fraction of the two kinds of fillers in NBR composites was 10%. The friction coefficient and wear rate of NBR were largely reduced by adding nano-Fe3O4 particles. The friction coefficient and wear rate of NBR were slightly reduced by adding low amount of nano-SrO.6Fe2O3 particles. However, the friction coefficient and wear rate increased with the increasing addition amount of nano-SrO.6Fe2O3 particles. When the content of nano-particles was 10%, the NBR/Fe3O4 composites had good surface microstructure and homogenously distributed nano-particles in the composites.