Abstract: AimTo investigate the effect of baicalin on the hippocampal neuronal apoptosis and the expression of HSP70 in rats with focal brain ischemia-reperfusion injury. MethodsOne hundred and twenty male Wistar rats were randomly divided into six groups：sham operated group, ischemia-reperfusion group, nimodipine group and three baicalin groups，to which baicalin was administered at doses of 50, 100 and 200 mg·kg^-1, separately. The models of focal brain ischemia-reperfusion injury induced by middle cerebral artery occlusion (MCAO) were used in this study. HE stain was used to observe the pathological changes. Flow cytometry (FCM) was used for determination of neuronal apoptosis. HSP70 protein expression of the neurons was detected with immunohistochemistry. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of the mRNA level of HSP70. ResultsBaicalin can significantly relieve the pathological changes and inhibit apoptosis in hippocampus CA1 area, and at the same time increase the expression of HSP70 and HSP70 mRNA. ConclusionBaicalin can relieve brain damage induced by focal brain ischemia-reperfusion in rats, which may be related to inhibiting the process of the neuronal apoptosis. The mechanism of antiapoptosis effect of baicalin may be related to the promotion of transcription of HSP70 mRNA and increasing the expression of the protein.