Abstract: OBJECTIVE To investigate the potential mechanism of astragaloside IV(AS-IV) preconditioning on the proliferation and anti-apoptotic ability of bone marrow mesenchymal stem cells(BMSCs) under hypoxia in vitro. METHODS Normal group, model group and AS-IV different concentration groups were set; CCK-8 method was used to detect the effect of AS-IV on the proliferation activity of BMSCs; apoptosis model of BMSCs induced by H/SD, the apoptosis rate of BMSCs in each group was evaluated by TUNEL staining; Western blotting was used to detect the expression levels of apoptosis-related proteins Bcl-xl and caspase-3. RESULTS Apoptosis of BMSCs was successfully induced by H/SD, and cell proliferation viability of the AS-IV intervention group with different concentrations was significantly improved compared with the control group(P<0.01). There was a significant difference in AS-IV(1.28×10^–5, 2.56×10^–5, 5.12×10^–5mmol·L^–1) between the groups after intervention for 72 h and 24 h(P<0.05). There was no significant difference between AS-IV (1.02×10^–6mmol·L^–1) groups after intervention for 72 h and 24 h. Compared with the model group, with the intervention concentration increased, the apoptosis rate of the AS-IV intervention group decreased gradually(P<0.05). Compared with the model group, Bcl-xl expression was significantly up-regulated and caspase-3 expression was significantly down-regulated in the AS-IV group(P<0.01), while Bcl-xl and caspase-3 expression were not significantly different in the AS-IV+AG490(JAK2 blocker) group. CONCLUSION AS-IV can promote the proliferation and antiapoptosis ability of BMSCs under hypoxic environment, possibly by regulating the JAK2 pathway and affecting the expression of Bcl-xl and caspase-3.