Abstract: The Fe-Mo-Graphite (FM) and Fe-Mo-Ni-Graphite (FMN) composites were fabricated by P/M technology. The microstructure, component and the tribological behavior of these composites at room temperature, 320 ℃ and 450 ℃ were investigated. The results indicate that both kinds of composites were mainly composed of ferrites, pearlite, Fe₃Mo, Mo₂C, Fe₂MoC carbides, and small amount of compacted graphite. The content of pearlites in FMN was less than that in FM. It is suggested that the addition of Ni element affect the formation and growth of the pearlite. At room temperature, the surface layer rich in graphite in sliding contact was contributed to the low friction of these composites. At elevated temperature, graphite and Fe oxides on the surface of counterparts, such as Fe₂O₃, Fe₃O₄ and FeO·Cr₂O₃ played the key role on decreasing friction and reducing wear.