Objective:the study is to observed the protective effects of ligustrazine on acute brain ischemia reperfusion injury in rats.Method:the content of plasma nitric oxide (NO) and middle molecule substance(MMS) and the content of brain tissue malondialdehyde(MDA) were detected using the models of incomplete brain ischemia reperfuing in rates by closing bilateral common carotid arteries.Result:ligustrazine could significantly increase nitric oxide content,reduced middle molecule sudstance and malondialdehyd content and viscosity of blood injury in rats.Conclusion:the protective effects of ligustrazine on cerebral ischemia injury may be related to its antilipid peroxidation and increased NO content and also decreased MMS level.