Aim Shengnai injection (SMI) , a Chinese patent medicine deprived from an ancient Chinese herbal compound Shengmai san, which is used extensively for the treatment of cardiovascular and cerebrovascular disease in clinic.To determine the neuroprotective effect of SMI, the effect and the relevant mechanism of SMI had been investigated on cerebral ischemiareperfusion injury in mice.Methods Right middle cerebral artery was occluded by inserting a thread through internal carotid artery for 1 h, and then reperfusion for 24 h in mice.Neuroprotective effect was testified using transmission electron microscopic examination, evaluation of infarct volume and neurological deficits.Related mechanism was evaluated by western blotting.The SMI was injected intraperitoneally after ischemia for1 h at doses of 1.42, 2.84 and 5.68 g · kg1.The control group received saline as vehicle of SMI.Results SMI(1.42, 2.84 and 5.68 g · kg1) could significantly reduced the infarct volume, SMI (5.68 g · kg1) could significantly improved the neurological deficits, as well as the neuron s morphology change.SMI (5.68 g · kg1) could significantly inhibited the autophagyrelated proteins: Beclin1 and LC3.SMI (5.68 g · kg1) remarkably inhibited the phosphorylation of adenosine monophosphate activated protein kinase (AMPK), and downregulated the phosphorylation of inammalian target of rapamycin (mTOR) and Jun Nterminal kinase (JNK) after 24 h reperfusion.Conclusion The results indicated that SMI elicits potent protection against cerebral ischemia/reperfusion injury, which may partly be due to the inhibition in autophagy and related signal pathways.