In this study, porous TiO2/HA coating and petaling structured TiO2/HA coatings were prepared by micro-arc oxidation (MAO) on titanium (Ti) surface to enhance biocompatibility. Morphology, phase composition, roughness and hydrophilicity were separately investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscope (AFM), and contact angle meter. The biocompatibility was evaluated by in vitro cell co-culture experiment. The results revealed that, the surface roughness and hydrophilicity of petaling structured TiO2/HA coatings were much larger than that of the porous structured TiO2/HA. And with the increased density of the HA petals, the roughness and hydrophilicity increased. MC3T3-E1 cell adhesion, spreading, proliferation and ALP expression were most enhanced on TiO2/HA coatings with the maximum density of HA petals. The beneficial effect of structures on biocompatibility may be due to the improved surface roughness and hydrophilicity.