Background:Naloxone hydrochloride injection produced by Guang dong Kangli Company was applied to treat acute infarction,which acheived markedly effect.It was found recently,when cerebral ischemia and infarction,hypothalamus arcuate nuclei release much β -endorphin,which inhibited neuron activity and made secondary lesion of CNS heavier.Further lead to disturbance of limb,mentality change even coma.Naloxone might resist blood flow decrease caused by β -endorphin,enhance oxgen supply of brain tissue,lighten lesion of cerebral perfusion.