Hydroxyapatite powders (HAp
Ca10(PO4) 6(OH)2) hybridized with 0-5 mass % Al2O 3 were prepared from calcium hydroxide and di-aminonium hydrogenphosphate by a wet chemical synthesis. Ethylacetoacetate Aluminum Diisopropoxide (Al(OC3H7)2(C6H 9O3)) was used as a source for aluminum oxide. The obtained powders were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) specific surface area measurement, and magic angle spinning-nuclear magnetic resonance spectroscopy (MAS-NMR). The X-ray diffraction patterns showed no Al2O3-peaks irrespective of Al2O3 content, suggesting that the Al2O 3-hybridized HAp powders were single phase. The Al2O 3-hybridized HAp powder had larger specific surface area. According to MAS-NMR analysis, it was considered that the aluminum element existed as aluminum oxide, it was not substituted for the Ca2+, PO 4 3-, or OH- ions.