OBJECTIVE： To investigate the protective effects of anemarsaponin B on hypoxia/reoxygenation injury astrocytes and its possible mechanism. METHODS： The primary astrocytes of neonatal SD rats were cultured and identified， and then randomly divided into normal group， model group， positive control group （nimodipine， 10 μmol/L）， anemarsaponin B low-dose， medium-dose and high-dose groups （1， 10， 100 μmol/L）， respectively. Normal group and model group were given complete medium 1 000 μL. Administration group was given complete medium with relevant medicine 1 000 μL. Except for normal group， hypoxia/reoxygenation injury model was established by oxygen-glucose deprivation/reperfusion in other groups. After reoxygenation， relative release rate of lactate dehydrogenase （LDH） in cell was detected by colorimetry. MTT assay was used to detect the relative viability of the cells. The contents of aquaporin 4 （AQP-4）， IL-6， IL-1β and TNF-α in cell were measured by ELISA. RESULTS： Compared with normal group， relative release rate of LDH， the contents of AQP-4， IL-6， IL-1β and TNF-α in cell were increased significantly in model group， while relative viability of the cells were decreased significantly （P＜0.01）. Compared with model group， relative release rate of LDH， the contents of AQP-4， IL-6， IL-1β and TNF-α in cell were decreased significantly in administration groups， while relative viability of the cells were increased significantly （P＜0.05 or P＜0.01）. CONCLUSIONS： Anemarsaponin B can significantly decrease cell injury degree， strengthen cell viability and protect hypoxia/reoxygenation injury astrocytes to certain extent. The effect may be related to the down-regulation of the secretion of AQP-4， IL-6， IL-1β and TNF-α.