The influence of hemostatic materials in split thickness calvarial bone defects was evaluated in 24 white rabbit models. The rabbits were divided in 4 groups. In the group A, Surgicel(R) was inserted into the 2x2cm sized left calvarial defects. In the group B, Gelfoam(R) was inserted and in group C, Bonewax(R) was inserted and in group D, Collagen bloc was inserted. The contralateral side underwent sham operation as the control group. After 4 and 8 weeks, radiological findings, histopathological findings and immunohistopathological findings were studied to find development of trabeculae, appearance of osteoblast, calcification and increased expression of TGF-beta. As a result, osteoid and osteoblast were richly found in Surgicel(R), Gelfoam(R), Collagen bloc inserted groups. In Bonewax(R) inserted group, bone regeneration was delayed and foreign body reaction was seen in 4 weeks and it reduced in 8 weeks. The TGF-beta was darkly stained in periosteum, connective tissue and periphery of bone defect. From this result it would be concluded as follows. Surgicel(R), Gelfoam(R) and Collagen bloc effects positively on bone healing with marked increasing of osteoid, osteoblasts and rapid bone remodeling. Bonewax(R) prolongs bone healing with increasing foreign body reaction. Bone regeneration was confirmed with increased expression of TGF-beta in Surgicel(R), Gelform(R) and Collagen bloc applied groups especially in periosteum and ends of bone defects. It suggests that bone regeneration was originated from these areas.