beta-tricalcium phosphate (beta-TCP) powder doped with monovalent or divalent metal ions was hot pressed at 1100 degrees C, and the effect of substitutional monovalent and divalent metal ions on mechanical properties of beta-TCP was investigated. The sinterability of PTCP would be enhanced by the substitution of monovalent and divalent metal ions for beta-TCP. Sintered beta-TCP doped with 7.6 Mol% Of Mg2+ ion showed a bending strength of 160 MPa. It was found that the substituition of Mg2+ ion up to 9.6 mol% and a small amount of monovalent metal ions for beta-TCP is effective to improve the mechanical strength of beta-TCP.