The formation, transference and failure of tribolayer were discussed during Cu-graphite sintered materials sliding against 45 steels under air atmosphere and different speeds. Under low speed, the tribolayer on the worn surface of Cu-graphite is smooth and compacted. However, at high speed, the tribolayer is rough and loose. The Cu-graphite was spalled under the convex effect of steel and flakes are engendered after grinding. Some Cu-graphite is transferred to the steel surface and a discontinuous layer is formed. The increase of the speed makes the form ability and compacted degree of surface layer decreased, and the failure of the tribolayer is aggravated, so the friction coefficient is high comparing with that at low speed.