Hydroxyapatite powder was synthesized by a citrate method, . Char-like precursor composed of Ca8(HPO4)2(PO4)4.5H2O (OCP) and CaCo3 was found via viscous resin-like intermediate by heating the mixed aqueous solution of Ca(NO3)2.4H2O(NH4)2HPO4 and citric acid. Resulted powder was transformed into hydroxyapatite phase by firing over 120$0^{circ}C$-135$0^{circ}C$ for 4 hr using the powder calcined at 90$0^{circ}C$ for 10 hr composed of mostly single hydroxyapatite phase. The sintered densities increased with firing temperature up to 130$0^{circ}C$ but the highest relative density was about 94% of theoritical value. indicating the presence of closed pores. The maximum 96 MPa of flexural strength was obtained at 120$0^{circ}C$ firing but the flexural strength showed lower values over the above sintering condition. Vitro test was performed by immersing of two jointed specimens in SBF for seven days and adhesion was observed between two specimens.