Pretreatment with scutellaria baicalensis stem-leaf total flavonoid has protective effects against ischemia and attenuates myocardial ischemia-reperfusion injury.In this study,rats were given scutellaria baicalensis stem-leaf total flavonoid intragastrically at 50,100,and 200 mg/kg per day for7 days before focal cerebral ischemia-reperfusion injury models were established using the suture method.We then determined the protective effects of scutellaria baicalensis stem-leaf tota flavonoid pretreatment on focal cerebral ischemia-reperfusion injury.Results showed that neurological deficit scores increased,infarct volumes enlarged,apoptosis increased and Bcl-2 and Bax protein expression were upregulated at 24 hours after reperfusion.Pretreatment with scutellaria baicalensis stem-leaf total flavonoid at any dose lowered the neurological deficit scores reduced the infarct volume,prevented apoptosis in hippocampal cells,attenuated neuronal and blood-brain barrier damage and upregulated Bcl-2 protein expression but inhibited Bax protein expression.Doses of 100 and 200 mg/kg were the most efficacious.Our findings indicate that pretreatment with scutellaria baicalensis stem-leaf total flavonoid at 100 and 200 mg/kg can improve the neurological functions and have preventive and protective roles after focal cerebra ischemia-reperfusion injury.