Cancellous bovine bone (CBB) as starting materials was treated by a series of degreasing and then calcined at low temperature. By adjusting the concentration of soaking solution NH4H2PO4 and the calcination temperature, β-TCP/HAP/Ca2P2O7 multiphasic bioceramic material was prepared with porous structure of natural bone. The phase composition of the calcined specimen was characterized by XRD and the reaction mechanism was discussed by FTIR and TG. Results show that the concentration of soaking solution NH4H2PO4 has a significant effect on the phase composition of the specimen. Porous bioceramic materials with different phase composition can be prepared by controlling the concentration reasonably. The phase composition was also influenced by the amount of OH- which came from HAP decomposition (x) and which reacted with NH4H2PO4 (3m). When x>3m, the product was mainly composed of HAP and β-TCP. When x<3m, the procuct may contain HAP/β-TCP/Ca2P2O7 or β-TCP/Ca2P2O7. Only as x=3m, pure β-TCP could be gained