Biphasic calcium phosphate foam consisting of core aTCP covered with carbonate apatite (CO3Ap) was fabricated based on the compositional transformation by exposing aTCP foam to (NH4)2HPO4 aqueous solution at 200 °C for 90min in order to understand the effect on bone formation rate and granule remaining ratio. The BCP foam was gently crushed and sieved to prepare foam granular. Bone defects made at the mandible of beagle dog were reconstructed with aTCP, BCP and CO3Ap foam granular. 3 months after surgery, bone reconstruction rate of the BCP and CO3Ap were 159.7±28.6% and 169.0±29.7% whereas those of aTCP and blood clot group were 89.5±14.7% and 85.2±13.2%, respectively, and no further increase was observed at 6 month. On the other hand, granular remaining ratio was 3.0±1.7%, 3.1±1.8%, 6.9±2.0% for BCP, aTCP and CO3Ap foam granular, respectivly. We concluded therefore, BCP foam granular could be an ideal bone substitute since it alllows large porosity, at least similar bone formation ratio to CO3Ap and faster replacement to bone.