Objective: To investigate the therapeutic effects of Shenxiong Huayu Capsule on cerebral ischemia reperfusion and its underlying mechanism in rats. Method : Male Sprague-Dawley rats (n=48) were divided randomly into four groups: sham group

model group

low dose of Shenxiong Huayu Capsule treatment group and high dose of Shenxiong Huayu Capsule treatment group. Global cerebral ischemia model was formed by improved four-vessel occlusion as described in the Pulsinelli's method. Changes in cerebral tissue morphous in hippocampal region were observed with light and electron microscopes 1d after operation. Learning and memory function (Morris water maze) were performed daily from 3d to7d after injury. Result: Compared with the sham group

the neurons

axons and capillaries in the models were damaged

and the latency to find the platform was prolonged(P＜0.05). Compared with the model group

the damage of brain tissue in the Capsule treated rats was decreased

latency to find the platform were shortened (P＜0.05). The above mentioned improvements were more significant in high dose of Shenxiong Huayu Capsule group. Conclusion: Shenxiong Huayu Capsule has good therapeutic effect on global ischemia-reperfusion injury and the mechanism is related to the attenuating of cerebral ultrastructure damage.