Abstract: Friction and wear behavior of Ultrahigh Molecular Weight Polyethylene (UHMWPE) was comparatively examined with a hip joint simulator. Wore surface morphology of UHMWPE was analyzed with a scanning electron microscope. The results show that wear rate of UHMWPE in multidirectional sliding model was higher than that in rotating model. In multidirectional sliding model, wear mechanisms were abrasive wear, adhesive wear and flaking resulting from plastic deformation. Wear mechanisms were mainly scuffing and light flaking due to fatigue in rotating model. Wear rate varied in different test environments because wear mechanism varied with test models. The hip joint simulator can evaluate wear behavior of prosthetic effectively.