Titanium alloys are excellent biomaterials with high mechanical property and high corrosion resistance. However, they have little or no bioactivity. If titanium alloys have a bioactivity, range of its application is largely extended. Prof. Takeshi Yao and Assistant Prof. Takeshi Yabutsuka have succeeded to fabricate highly bioactive titanium alloy. They formed micron-size holes on the titanium alloy with sandblast and made Apatite Nuclei, which are nano-size particles very active to induce hydroxyapatite from body fluid previously invented by Prof. Takeshi Yao, precipitate in the holes with no shape deformation and no mechanical property change. The high bioactivity was confirmed because the hydroxyapatite covered whole surface of the plates within 1 day by soaking in SBF. The hydroxyapatite layer showed more than 10 Mpa adhesive strength to the alloy due to a mechanical interlocking effect.