BACKGROUND: Concentrated growth factor (CGF) fibrin membrane is involved in metabolism regulation, which has been applied in bone remodeling. Previous Studies have found that the cytoplasts of osteoblasts, interstitial cells and osteocytes in distraction osteogenesis are positive for osteoprotegerin and receptor activator nuclear factor kappa B ligand (RANKL).OBJECTIVE: To explore the mechanism of bone orthopedic effect and the promotion effect of CGF fibrin membrane on the distraction osteogenesis of the rabbit mandible.METHODS: Twenty-four white rabbits were randomly selected. Distraction osteogenesis was performed unilaterally in the rabbit left mandible (control group); CGF fibrin membrane was fixed on the inner surface of distractor, and the distraction gap was then completely wrapped prior to distraction osteogenesis in the right mandible (experimental group).At 1, 7, 14 and 28 days of consolidation period, the rabbits were sacrificed and the bilateral mandibles were taken for hematoxylin-eosin staining, western blot assay and immunohistochemical staining to detect the expression of RANKL and osteoprotegerin in the newborn bones; the osteogenesis in the distraction gap was observed and compared between two groups.RESULTS AND CONCLUSION: The osteoprotegerin positive cells and positive area percentage in the experimental group were significantly higher than those in the control group at 1, 7 and 14 days after distraction osteogenesis (P < 0.01). The RANKL positive rate and positive area percentage in the experimental group were significantly higher than those in the control group at 1 and 14 days after distraction osteogenesis (P < 0.05 or P < 0.01). Western blot assay showed a higher ratio of RANKL/osteoprotegerin in the control group than the experimental group (P < 0.01). Our findings indicate that CGF fibrin membrane can promote osteogenesis and mineralization in the distraction gap of the rabbit mandible, which is beneficial for distraction osteogenesis in the mandible.