Fibroblast growth factor 9 (FGF9) plays complicated and crucial roles in bone formation, and the biologic effect of FGF9 may depend on the gene dosage, developmental stage, cell type, or interactions with other cytokines. In this study, we demonstrated that FGF9 enhanced the phosphorylation of extracellular regulated protein kinases 1/2 in calvaria-derived mesenchymal cells. However, the inhibitory effect of FGF9 on the osteogenic differentiation of calvaria-derived mesenchymal cells did not depend on the phosphorylation of extracellular regulated protein kinases 1/2. Combined with the previous findings that FGF9 promotes dental pulp stem cells chondrogenesis in vitro, we suggest that FGF9 may be applied to promote chondrogenesis and inhibit osteogenesis in mesenchymal stem cells in vitro.