Compared with model group, in 20 mg/kg icariside II group the neurologicalseverity score, cerebral water content and cerebral infarction volume, braintissue ROS content and MDA level were significantly decreased (P<0.05),and the brain tissue SOD, GSH-Px and catalase levels and Nrf2 and HO-1protein levels were significantly increased (P<0.05). This evidence concerns the gene CAT and brain infarction.