Calcium phosphate invert glass-ceramic coating is very effective for improving biocompatibility of low rigidity b-type titanium alloy, Ti-29Nb-13Ta-4.6Zr, that is expected to be used as an implant material. The matrix of calcium phosphate glass-ceramic coated Ti-29Nb-13Ta-4.6Zr is solutionized during coating process. Then the strength of calcium phosphate invert glass-ceramic coated Ti-29Nb-13Ta-4.6Zr decreases. In order to increase the strength of the alloy, aging treatment is effective. However, there will be the possibility for the coated layer to be failed during aging. The tensile properties of aged calcium phosphate invert glass-ceramic coated Ti-29Nb-13Ta-4.6Zr was investigated. Bonding strength between matrix and coated layer was also investigated. The strength of calcium phosphate invert glass-ceramic coated Ti-29Nb-13Ta-4.6Zr increases by conducting aging treatment. Cracking of the coated layer is occurred during aging when the thickness of the coated layer is 20 micro meters, but is not occurred when the thickness of the coated layer is 5 mm. Bonding strength between coated layer and matrix decreases by aging when the thickness of the coated layer is 20 micro meters, but does not decrease when the thickness of the coated layer is 5 micro meters.