Abstract: Three kinds of Al_2O_3-based ceramic tool materials composed of different additives suchas TiC,Ti(C,N) and SiC_w were investigated on the MRH-3 High Speed Ring-block wear tester.The stress distribution during friction and wear process was calculated by ANSYS.SEM was used to observe the ceramic surface.Different additives have a profound effect on the wear resistance of the Al_2O_3-based ceramic materials.The wear rates of the Al_2O_3-based ceramics increased with the increase of the ratio of elastic modulus and hardness,and decreased with the increase of fracture toughness.Adhesive wear was the predominant wear mechanism for Al_2O_3/TiC.While the wear mechanism of Al_2O_3/Ti(C,N) and Al_2O_3/SiC_w was abrasive wear.