〔Abstract〕 Objective To investigate whether fibroblast growth factor 18(FGF18) can induce human gingival fibroblasts(HGFs) isolatedin vitroto differentiate into osteoblast-like cells, and to explore the mechanism of osteogenesis. Methods HGFs were isolated, cultured and identified by tissue block method. The third generation of HGFs were divided into experimental group and control group. FGF18 and L-DMEM was added to the experimental group while L-DMEM was added to the control group.The effects of different concentrations of FGF18(0, 0.01, 0.02, 0.04, 0.06 mg/L) on proliferation of HGFs were detected by Methylthiazolyldiphenyl-tetrazolium bromide(MTT) assay. Alkaline phosphatase(ALP) and alizarin red staining were used to detect the osteogenesis and mineralization ability of the cells after induction. RT-PCR, immunocytochemistry staining, and Western blot were used to detect the expression of genes and proteins related to osteogenesis and BMP2 in the BMP signaling pathway. Results Compared with the control group, the experimental group could promote the proliferation of HGFs at 3, 5, 7, 9, and 11days(P<0.05),ALP activity and mineral salt deposition increased after induction at 14 and 21 days(P<0.05), and the expressions of ALP, OPN, OCN mRNA and BMP2 mRNA in BMP signaling pathway significantly increased(P<0.01). The expressions of OPN, OCN and BMP2 protein at 21 days were significantly higher than those at 14 days(P<0.01). Conclusion FGF18 can promote the proliferation of HGFs, and induce the differentiation of HGFs into functional osteoblasts. The osteogenic mechanism is related to the upregulation of BMP2.