Wear is the primary cause of failure of joint replacement prostheses. Poly(ether-ether-ketone)(PEEK) was reinforced with nano-Al2O3 particals of various mass fractions in this study. The effect of nanometer Al2O3 mass fractions on the contacted angle of the reinforced PEEK composites was investigated. Tribological properties of composites under distilled water and physiological saline lubrication condition was measured. And the morphologies of the worn surfaces were observed with optical microscope. The results shows that the wettability and wear resistance were all improved with appropriate nano-Al2O3.The wear resistance of composites filled with 7% nano-Al2O3 was the best under both distilled water and physiological saline lubrication. In addition, it can be found that there is serious plough on the surface of pure PEEK. This indicated that serious fatigue wear occurred on the worn surface of pure PEEK. Moreover, there are only light fatigue wear on the worn surfaces of PEEK composites filled with nano-Al2O3.