Abstract: Using the M-2000 tribology machine, without lubrication, the tribology properties of two kinds of graphite and two kinds of C/C composites were studied with GCr15 steel as couple. The results show that C/C composites own the lower friction coefficient and bulk worn loss than the graphite. Both the friction coefficient and bulk worn loss of C/C composites with the smooth lamination(SL) carbon matrix structure are lower than the two of C/C composites with rough lamination (RL) structure. The low density graphite gets higher friction coefficient and bulk worn loss than the high density graphite. With time prolonging, the friction coefficient of RL C/C composites increased under 60 N,80 N and 200 N while others decreased. But the friction coefficient of SL C/C composites decreased except 60 N and changed a little, and that of two kinds of graphite increased. The SEM show that the friction film of RL C/C composites becomes more integrate with increasing load, while that changes only a little of SL C/C composites. The friction film of high density graphite is more integrate than the low density graphite. C/C composites have advantage over graphite used as the seal ring of the main axis of turbine engine for airplane.