Abstract: Objective To investigate the effects of oligo poly (ethylene glycol) fumarate/graphene oxide (OPF/GO) on differentiation of bone marrow mesenchymal stem cells (BMSCs) in rats. Methods OPF/GO hydrogel were prepared via physical mixing.Then BMSCs were encapsulated in OPF/GO hydrogel and co-cultured in osteogenic medium.After 3, 7, 14 and 21 days, the morphology and osteogenic differentiation of BMSCs were detected by histological staining (HE staining, Von Kossa staining and alizarin red staining) and immunofluorescence staining. Results Cells encapsulated in composite hydrogel were stained for histological examination and immunofluorescence staining at different time points (3, 7, 14 and 21 days), and it was found that BMSCs grew and proliferated well in the hydrogels.With the extension of osteogenic induction, mineralized nodules and osteogenic gene expression gradually increased.Moreover, compared with OPF hydrogel, the OPF/GO could improve the osteogenenic differentiation of BMSCs significantly. Conclusion OPF/GO hydrogel has good biocompatibility and it can induce the osteogenenic differentiation of BMSCs effectively.