Micro-arc oxidation is a new surface treatment method, but the structure of the micro-arc oxidation coating is limited to the electrolyte composition. In this paper the micro-arc oxidation coating on Ti6Al4V alloy was modified by addition of micro- Al₂O₃ particles to a sodium phosphate solution. The coating structure and phase was characterized by scanning electron microscopy and X-ray diffraction, and the oxidation resistance and thermal shock properties of the coating were investigated. Results showed that a coating denser than the original coating was produced. This new coating was composed of Al₂TiO₅ and TiO₂. The oxidation resistance and thermal shock property of the coating improved with addition of Al₂O₃ particles to the electrolyte relative to the sample prepared without the particles in the electrolyte. Moving Al₂O₃ particles were adsorbed on the coating surface and penetrated through it. As a result, the phase structure and properties of the original coating were modified.