The distribution and function of transforming growth factor-beta (TGF-β) in the regionof bone defect repaired by collagen/nano-beta-tricalcium phosphate composite artificial bone (Co/N-TCP) and the ability of Co/N-TCP recruiting osteoblasts to precipitate the repair of bone defectwere investigated. Twenty-four domestic rabbits were operated on bilateral cranial bone to create anexperimental bone defect of 8.0 mm in diameter through the whole bone. On the left, Co/N-TCPwas implanted as experimental group, but on the right, Co/TCP was implanted as control group.At 2nd, 4th, 8th, 12th week after operation, all animals were sacrificed and the implanted materi-als with surrounding bone were taken out. Immunohistochemical staining was performed for TGF-βassay by avidin-biotin complex method (SABC). Simultaneously, TGF-β was quantitatively ana-lyzed by HPIAS-1000 imaging analysis system. The inmmunohistochemical staining for TGFβ re-vealed that osteoblasts and immature osteocytes highly expressed TGF-β. Diffused TGF-β positivestaining particles appeared in the mesenchymal and fibrous-tissue. There was no significant differ-ence in the TGF-β positive staining between two groups in the medial region to original osseous bedsat different time points (P＞0. 05). However, in distal original osseous bed of the defected region,the positive expression of TGF-β in the Co/N-TCP group was significantly stronger than in the con-trol group (P＜0.05 or 0.01). The Co/N-TCP has good bioactivities and ability of stimulating andconducting TGF-β to aggregate and precipitate the healing of bone defect.