Abstract: OBJECTIVE To observe the protective effect of schisandrin B on BV-2 microglia injury stimulated by H₂O₂, and investigate its possible mechanism. METHODS BV-2 cells were cultured in vitro and H₂O₂ was used to induce the oxidative stress model of cells. The cells were divided into 5 groups:control group, model group, schisandrin B treatment groups (10, 20, 40 μmol·L^-1). CCK8 kit was used to measure the relative survival rate of BV-2 cells and related kits were used to analyze the levels of MDA, NO and the activity of SOD. Western Blot was used to determine the expression levels of Jak2, p-Jak2, State3, p-State3, HO-1 and SOD1. RESULTS Compared with model group, the BV-2 cells relative survival rates and the activity of SOD after treatment with different concentrations of schisandrin B were significantly increased, while the expression levels of MDA and NO were significnatly decreased (P<0.05). The results of Western blot indicated that the expression levels of p-Jak2 and p-State3 were significantly decreased after treatment for schisandrin B, while the levels of HO-1 and SOD1 were greatly increased (all P<0.05). CONCLUSION Schisandrin B can significantly inhibit the oxidative stress injury of BV-2 cells and its underlying mechanism may involve in suppressing the activation of Jak2/State3 signaling pathway.