Abstract: To investigate the protective effect of Zige lyophilized powder on brain microvascular endothelial cells( BMECs) after hypoxia- reoxygenation injury. BMECs of the 10 d rats were isolated and cultured,the model of BMECs with the hypoxia- reoxygenation injury was estabished by DMEM sugar- free medium,three gas incubator oxygen container( lacking oxygen and sugar for 2 h),and 5% CO2 incubator for 24 h after oxygen training. The proliferation of endothelial cells was detected by MTT method. The protein expression levels of MMP- 9 were detected by WB method. Zige lyophilized powder( 49.00,98.00 μg·m L^-1) could promote BMECs proliferation in hypoxia- reoxygenation model.The increasing level of MMP-9 protein in a hypoxia- reoxygenation injury on cultured BMECs was inhibited significantly by Zige lyophilized powder( 24.50,49.00 and 98.00 μg·m L^-1)( p < 0.05). It showed that the possible mechanism of Zige lyophilized powder for injection on protecting the cell integrity would be associated with the decreasing MMP-9 protein expression.