【Abstract】Objective To explore the effect of PA on the apoptosis and proliferation of brain microvascular endothelial cells induced by H2O2. Methods The mouse brain microvascular endothelial cell line bEnd.3 was cultured in vitro and randomly divided into NC group (normally cultured cells), H2O2 group (H2O2 concentration 100 μmol/L), H2O2+PA 10 μmol/L group (H2O2 concentration 100 μmol/L, PA concentration 10 μmol/L), H2O2+PA 20 μmol/L group (H2O2 concentration 100 μmol/L, PA concentration 20 μmol/L), H2O2 + PA 40 μmol/L group (H2O2 concentration 100 μmol/L, PA concentration 40 μmol/L). MTT method was used to detect cell survival rate. Flow cytometry was used to detect the apoptosis rate. The levels of LDH, MDA, CAT, SOD, GSHPx, ROS were detected. Western blot was used to detect the expression of Cleared caspase3. Results Compared with the NC group, the cell survival rate and the levels of CAT, SOD and GSHPx in the H2O2 group were significantly reduced (P ＜005), and the levels of LDH, MDA and ROS were significantly increased (P ＜005), the level of caspase3 protein was increased significantly (P＜005). Compared with the H2O2 group, the cell survival rate and the levels of CAT, SOD, GSHPx in H2O2+PA 10 μmol/L group, H2O2+PA 20 μmol/L group, H2O2+PA 40 μmol/L group were significantly increased (P＜005), the levels of LDH, MDA, and ROS were significantly reduced (P＜005), and the apoptosis rate and the level of Cleared caspase3 protein were significantly reduced (P＜005). Conclusion Poriac acid could inhibit H2O2induced apoptosis of cerebral microvascular endothelial cells and promote cell survival.