Objective To investigate whether diazoxide preconditioning protects cerebral against brain ischemia reperfusion via mitochondrial calcium uniporter or not.Methods The ischemia reperfusion models were performed by thread occlusion of middle cerebral artery for 2h,and then 24h reperfusion.32 rats were randomly divided into four groups:A group(sham-operated group), B group(ischemia reperfusion group), C group(diazoxide group), D group(diazozide-spermine group).After 24h reperfusion,neuropsychological score,the activity of superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px),the content of malondialdehyde(MDA) and nitric oxide(NO) were observed in above groups respectively.Results Compared with B group,diazoxide preconditioning of C group improved neuropsychological score(P＜0.01),improved the activity of SOD and GSH-Px（P＜0.05）,and decreased the content of MDA and NO（P＜0.05）. Compared with C group,spermine attenuated the effects of diazoxide preconditioning of C group, which improved neuropsychological score(P＜0.01),improved the activity of SOD and GSH-Px（P＜0.05）,and decreased the content of MDA and NO（P＜0.05）.Conclusions The effects of diazoxide preconditioning against brain ischemia reperfusion by attenuating peroxidation injury in rats may involve in the suppression of MCU during reperfusion.