Abstract: Objective：To investigate the effect of the hydroxyl safflor yellow A in regulating the stemness and the activity of osteogenic differentiation of bone marrow stromal cells(BMSCs) in vitro. Methods: Tissue adherent culture was used to isolate the BMSCs from female mandibular，and CCK-8 method was used to detect the effect of different concentrations of HSYA on the growth of BMSCs. The stemness transcription factors (NANOG，SOX2，OCT4) were detected by Western blot and RT-PCR in BMSCs supplemented with HYSA. The colony-forming efficiency was compared between HYSA group and control group. The different osteogenic ability of the HYSA group, positive group and the control group was analyzed by real-time RT-PCR，Western blot and Alizarin red staining after osteogenic induction. Results: Compared with the control group, the levels of NANOG, SOX2, and OCT4 of HYSA group were higher than that of the control group, and there was statistically significant difference. Seven days later osteogenic induction in vitro the of osteogenic differentiation genes were increased in the experimental group BMSCs. 14 days later osteogenic induction, the calcium nodules of HYSA group were more than that of the control and positive group. Conclusions: HYSA can promote the proliferative capacity of BMSCs, and induce their osteogenic differentiation, due to the participation of Runx2，OCN，OSX，OPN.