This study evaluated the histology results of surgically created bone cavities in the calvaria of rabbits that were subsequently filled with a HA/ß-TCP composite powder developed in Korea (Dentium, Korea). Ten young adult rabbits were used. Four defects were surgically produced in the calvaria of each rabbit. These defects were classified into 4 groups: the control group, no graft materials; experimental group I, normal saline + graft materials; experimental group II, venous blood + graft materials; and experimental group III, graft materials only. The defects were randomly filled with the graft materials. The rabbits were sacrificed with at 1-, 2-, 4-, 6- and 8- weeks after surgery. The histology specimens were prepared using the general method with H & E staining at a 6 ㎛ thickness. Histologically, the degree of new bone formation was similar in all experimental groups. However, for experimental group II, many cells had gathered around the graft materials 1-week after surgery, and new bone formed slightly faster and than in the other groups. No bone formation was observed in the control group. Based on histology findings, the new HA/ß- TCP composite powders appeared to act as a scaffolding material for the regeneration of osseous defects.