M50 steel was widely applied to manufacture aircraft bearing whose service life was mainly determined by its tribological behavior. The primary purpose of this study was to investigate the tribological behavior of M50-5 wtAMoS(2) composites (MMC) sliding against Si3N4 balls from 150 to 450 degrees C at 20N-0.2 m/s. The results showed that the excellent tribological performance of MMC was obtained for the lower friction coefficient of 0.17-0.62 and the less wear rate of 1.9-3.5 x 10(-6) mm(3)N(-1)m(-1) at 150-450 degrees C, which was attributed to the formed lubricating structure consisting of the lubricating film mainly containing massive MoS2 and FeS, as well as underneath compacted layer. The enriched added MoS2 and FeS generated during the sintering process in the lubricating film could provide good lubrication from 150 to 350 degrees C, while FeS for its excellent plastic flow capacity from 350 to 450 degrees C was well spread out on the friction surface to realize the lubricating role continuously, which made MMC maintain a long-lasting lubricating performance. The compacted layer played the role in supporting the lubricating film to prevent it from being damaged. (C) 2017 Elsevier B.V. All rights reserved.