By using ethylene diaminetetraacetic acid (EDTA) and citric acid as the complexants, hydroxyapatite (HA) coatings were fabricated by means of one-step micro-arc oxidation (MAO) in the acid electrolytes containing Ca2+ and P5+ions. With the increase of Ca/P in the electrolytes, the content of HA in the coatings obviously increased and the coatings possessed coarser surfaces with fine and well-distributed pores. The results of animal experiments have indicated that the inflammatory reactions induced by implant buttons with HA coatings were minor and the new musculature could grow on the surfaces of the coatings.