OBJECTIVE：To study the effects of chrysophanol on the activa tion of microglia and the expression of inflammatory factors in cerebral ischemia model rats. METHODS ：SD rats were randomly divided into sham operation group ， model group and chrysophanol high ，medium，low dose groups [7.88，3.94，1.97 mg/（kg·d）]，with 20 rats in each group （the number was complemented in cases of death or unsuccessful modeling during modeling process ）. Except for sham operation group ， middle cerebral artery occlusion model was established in other groups by improved thread method. After 2 hours of ischemia ， sham operation group and model group were intraperitoneally injected with 1 mL normal saline ，and each administration group was intraperitoneally injected with 1 mL corresponding drug ，once a day ，for 7 consecutive days. After last medication ，the score of neurological impairment was recorded ；cerebral infarction of rats was observed by TTC staining ，and the percentage of cerebral infarction area was calculated. The expression of Iba- 1 positive cells in ischemic penumbra of rats was observed by immunofluorescence staining. The expression of Notch- 1，TNF-α and ICAM-1 in the ischemic penumbra of rats were detected by Western blotting assay. RESULTS ：In sham operation group ，there was no infarction area in the brain tissue ，and the Iba- 1 positive cells in the ischemic penumbra were few and branched. Compared with sham operation group ，the infarction area of cerebral tissue in rats was obvious in model group ； the 052）number of Iba- 1 positive cells in ischemic penumbra were 〔ZQ2017003〕） increased significantly ，and they were in amoeba or round shape；the neurological impairment score ，the percentage of cerebral infarction area ， relative expression of Notch- 1， TNF-α and ICAM-1 protein in ischemic penumbra were increased significantly （P＜0.05）. Compared with m odel rats ，the infarction area of cerebral tissue in each dose group of chrysophanol was reduced to different extent ；the number of Iba- 1 positive cells in ischemic penumbra was decreased ；neurological impairment score ，the percentage of cerebral infarction area ，relative expression of Notch- 1，TNF-α and ICAM-1 protein were significantly decreased （P＜0.05 or P＜0.01）. CONCLUSIONS ：Chrysophanol has a certain protective effect on the brain tissue of cerebral ischemia model rats ，and can relieve the nerve injury. Its mechanism may be associated with inhibiting the activation of microglia and expression of inflammatory factors mediated by Notch pathway.