Abstract: In order to reveal the wear mechanism of ceramic cutting tools in real cutting process, a simulationtest was carried out on a block-on-ring tribometer. The investigation was conducted at ambienttemperature to determine the wear behaviour of ceramic/metal tribo-systems under boundarylubrication of water and oil. In this test, the boundary lubrication conditions were provided bydropping oil or water into contact area at a rate of 5 drops per minute (about 0.1 ml/min). Thetested materials are Al2O3-Ti(CN) composite ceramic, Al(purity>99.5 wt pct), Fe(C<0.04 wtpct) and a stainless steel (ASTM 302), which combined into three ceramic/metat frictional pairs.The test results indicate that wear loss of the materials increases with load and speed. Comparedwith unlubricated conditions, the boundary lubrication condition made the materials wear moreserious, which show that lubricating method is very important to a tribo system, and unsuitablelubricating method could increase the wear of materials instead of reducing it. The sudeces ofthe ceramic and the metallic samples were analysed by using a scanning electron microscopewith energy-dispersive X-ray attachment, which indicate that material transfer occurred betweenthe ceramic and metallic materials. The wear mechanism was discussed.