Abstract:[Objective] To explore the effect of microRNA (miR-210-3p) transfection in rat bone marrow mesenchymal stem cells (BMMSCs) on their osteogenic capacity. [Methods] Rat BMMSCs were isolated and cultured in vitro, and were randomly divided into 3 groups. The cells in the blank control group, MiR-210-3p enhanced group (enhanced group) and miR-210-3p inhibited group (inhibited group) were given transfection with the corresponding genes in vitro respectively. The cell biological behavious were detected, involving proliferation, apoptosis and migration, as well as osteogenic differentiation and adipogenic differentiation, in addition, qRT-PCR was used to detect mRNA expression levels of corresponding markers. [Results] The third generation BMMSCs obtained in this study were positive for CD44 and CD90, negative for CD34 and CD45, which were consistent with the surface antigen characteristics of mesenchymal stem cells. Compared with blank control group, mRNA expression of miR-210-3p in enhanced group was significantly increased (P<0.05), whereas which in the inhibition group was significantly inhibited (P<0.05). The OD value of cell proliferation, Transwell cell migration and alizarin red staining calcium deposition count were significantly ranked from high to low as the enhanced group > blank control group>inhibition group (P<0.05). Conversely, the apoptosis rate and oil red O staining lipid drop count were significantly ranked from low to high as the enhanced group<blank control group< inhibition group (P<0.05), As results of qRT-PCR assay, the mRNA relative expression level of osteo-genic genes, including ALP and Bglap-2, was significantly ranked from high to low as the enhanced group>blank control group>inhibitiongroup (P<0.05) , whereas the mRNA relative expression levels of lipid-expressing genes, including PPARγ and LPL, were from low to highas the enhanced group<blank control group<inhibition group (P<0.05) . [Conclusion] In this study the miR-210-3p does promote osteogen-ic differentiation, inhibit adipogenic differentiation, reduce apoptosis, and promote cell proliferation and migration of BMMSCs in rats.