목적: In the injured bone, it has a limited capacity for self-repair. The aim of this study was to explore bone regeneration effect of horse bone powder in vivo. We prepared 5 μm and 100 μm sized-horse bone cements and compared their efficiency with bovine powder (Bio-oss). 방법:In this study, we used 10 New Zealand white rabbits and four-round shaped defects were made in the parietal bone (diameter 6 mm). Experimental defects were filled with Bio-oss, 5 μm horse bone cements and 100 μm horse bone cements. The specimens were collected after 6 and 12 weeks. Bone formation was evaluated by microscopic computerized tomography (micro-CT) and stained by hematoxylin and eosin. 결과:There was significant difference of bone formation between the 100 μm size horse bone cement group and the control group at 6 and 12 weeks. The total bone volume was 33.36% ( 9.9%) in the control group at 12 weeks after operation and 46.12% (10.04%) in the 100 μm size horse bone cements group. In the histology, we discovered compactible bone-formation in the 100 μm size horse bone cement group, whereas the 5 μm size horse bone cement group exhibited inhibitory effect. 결론:The 100 μm horse bone cement significantly induces bone regeneration in bone defect areas and may be used as a bone regeneration materials.