Abstract: A description is given of the effect of hight emperaturet reatment on tribological properties of carbon/carbon(C/C) composites prepared by chemical vapour deposition. The curve diagram of brake moment-brake time of different temperaturet reated samples was anayzed. The results indicated that the average dynamic frictional coefficient(FC) of C/C composites was decreased in drycondition, but dam pcondition average dynamic FC and drycondition averagestatic FC were increased as temperature was increased. After C/C composites were treated under 2500℃, they had smooth brake process and small wear, and their average dynamic FC was slowly decreased in dampcondition. The average dynamic FC of four kinds of samples treated under different temperatures was reduced in dry and dampcondition as brake pressure and energy were raised.