Surface modification of hydroxyapatite(HA) powder was performed with r-aminopropyl silane in toluent solvent. The modification effects were characterized by using XPS and FT-IR methods. The results indicated that the P2p electron binding energy of the modified HA decreases 0.4eV compared to that of HA. Furthermore, a new peak, 998cm-1 absorption appeared in IR differential spectra of modified HA and HA, which is due to a stretching vibration of structure P-O-Si, meaning that a direct covalent bonding between hydroxyl group on HA surface and the organic silane molecule was realized after modification, and the chemical bonding type was P-O-Si. The formation of the above structure suggested that the more effective interfacial adhesion between the modified HA and polymer matrix could be carried out.