Different micro-arc oxidation coatings were fabricated on ZL108 alloy in the silicate electrolyte without and with In2S3. Scanning electron mi-croscope (SEM), Optical Profiler, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical workstation and so on were used to study the influence of In2S3 on the microstructure, phase composition, corrosion resistance，micro-hardness and thickness of the MAO coating. The results showed that the addition of In2S3 can increase the voltage of the MAO, promote the MAO coating formation rate and increase the coating thickness. The coating formed containing In2S3 was denser and the micro-hardness of the coating was increased. Therefore, the corrosion resistance of the coating with In2S3 was improved. The main phases of all the MAO coating were α-Al2O3, γ-Al2O3 and SiO2. The XPS result showed that In2O3 was formed on the coating surface. As a consequence, adding In2S3 can optimize the structure of the MAO coating and enhance its comprehensive properties.