Abstract: The wear mechanisms of a new silent chain and a conventional silent chain meshing with the outside flanks of the links were comparatively investigated using a high-speed chains test rig. The worn surfaces of the pins were observed using a scanning electron microscope. And the effects of the testing temperature and fluctuant speed on the wear resistance of the new silent chain were examined. It was found that the new silent chain had much better wear resistance than the conventional silent chain meshing with the outside flanks of the links, which was attributed to the special structure and the load and speed characteristics of the new silent chain. Moreover, the new silent chain recorded a larger wear elongation ratio at elevated temperature than at room temperature, and it had a larger wear elongation ration at fluctuant speed than at constant speed as well. This was related to the enhanced frictional thermal effect at elevated temperature and the more severe fatigue and wear damage at fluctuant speed.