Copper-based friction materials containing flexible graphite,granular graphite and squama graphite were prepared by powder metallurgy sintering technology respectively,and the effect of different types of flaky graphite on tribological properties of friction materials at different braking speeds was investigated.The results show that the differences of density and mechanical strength on the friction materials prepared by different types of graphite influence the microstructure form of the material matrix during the braking process,and cause different wear mechanism of the friction surface.The main wear mechanism of flexible graphite friction materials is oxidation wear,the main wear mechanisms of granular graphite friction materials are plowing wear and abrasive wear,while the main wear mechanisms of squama graphite friction materials are plowing wear and adhesive wear.The friction materials with granular graphite show relatively smaller friction coefficient fluctuation under different braking speed and repeated single braking,possess the best comprehensive tribological properties due to its stabilized friction coefficient and moderate wear loss.