Abstract: 2024-T4 aluminum alloy was treated by micro-arc oxidation in the silicate system electrolyte with different concentrations of nano Cr2O3 microparticles. The surface morphology and the cross-section morphology of ceramic coatings were observed by SEM. The distribution of main component of ceramic coatings along the cross-section was analyzed by EDS, and the phase structure of ceramic coatings was analyzed by XRD. The hardness of ceramic coatings was measured by nano indentation hardness tester. The surface roughness of ceramic coatings was measured by roughness meter. The friction coefficient of ceramic coatings was measured by Friction and wear tester. The wear volume of ceramic coatings were measured by laser confocal microscope and the wear rate was evaluated. The morphology of wear tracks was observed by SEM. The results show that the composition of Cr2O3 was discovered in the ceramic coatings after nano Cr2O3 microparticles were added to the electrolyte. The hardness of ceramic coatings is the highest, the friction coefficient of ceramic coatings is the minimum, the wear rate is the lowest, and the wear resistance of ceramic coatings is the best under the condition of concentration of nano Cr2O3 microparticles being 2.4 g/L in the electrolyte.