Abstract: Mo/Al₂O₃composites with various compositions were sintered under pressureless conditions The wear behavior and wear mechanism of Mo / Al₂O₃ composites were studied Results indicated that the wear rates initially increased with the increasing volume fraction of Mo At 30 % to 60 % , the wear rates decreased as the volume fraction of Mo increased A marked increment in wear rate can be found as the volume fraction increased from 60% to 70 %. At 10 % and 20 % , the friction coefficients were low The composites exhibited good wear resistance when the volume fraction of Mo was higher than 60 % and MoorAl₂O₃ was continous. The wear mechanisms were brittle break off for composites with low Mo fraction , and abrasive wear for composites with high Mo fraction