This study is to evaluate the biocompatibility of HAP/Ti gradient coating by microarc oxidation and biomimetic process. Titanium alloys were activated by microarc oxidation (MAO), and immersed in simulated body fluid to prepare HAP/Ti gradient coating. Scanning electron microscopy (SEM) had been used to investigate the microstructure of the coatings. The biocompatibility of the coatings was evaluated by animal acute and subacute toxicity test, micronucleus test, hemolysis test, and oral mucosa test. The results showed HAP/Ti gradient coating was successfully fabricated on the substrate. The animal experiment showed the coating had not short-term toxicity, oral mucosa irritation, and micronucleus occurrence rate was 3.2 ‰ and hemolysis rate was 2.5%. The HAP/Ti gradient coating made by MAO and biomimetic process showed good bio-security and compatibility, it may be new oral implant materials.