Anodic oxidation was applied to produce nanostructures on the surface of titanium (Ti) implants. The bioactivity of the Ti implants was evaluated by simulated body fluid soaking test. The biocompatibility was investigated by in vitro cell culture test. The results showed that bone-like apatite was formed on the anodized Ti surface, but not on the as-polished Ti surface after immersion in simulated body fluid for 2 weeks. Cells cultured on the anodized Ti surface showed enhanced cell adhesion and proliferation, compared to those cultured on the as-polished Ti surface. Based on these results, it can be concluded that anodic oxidation improved the bioactivity and biocompatibility of Ti surface, which was attributed to the formation of nanostructures as well as the nanostructure induced high surface roughness and hydrophilicity.