Abstract: Ceramic layers were obtained by the micro-arc oxidation technology on LY12 aluminum alloys. The wear resistance properties of ceramic layers at room temperature were tested and analyzed. The experimental results indicate that the surface wear profile of micro-arc oxidized ceramic layers is regular and the hardness of ceramic layers is 10 times more than that of substrate. It is concluded that the wear resistance capability and hardness of aluminum alloys can be remarkably improved by the micro-arc oxidation technology.