Objective To observe the effect of YiZhikoufuye(YZ) on apoptosis in the different cerebral regions of experimental Alzheimer's disease(AD) rats.Methods The animal model of AD was set up by stereotaxic damage of CA1 area of rat hippocampus using aggressive A?1-40.After operation thirty male Wistar rats were randomly divided into YZ,melatonin and model control groups,10 in each group.The rats were fed with YZ, melatonin and saline,respectively.On the 41th day,the rats were killed.The percentage of apoptotic cells,the changes of mitochondrial membrane potential and the expression level of cytochrome C protein were observed with immunohistochemical methods.Results Compared with control group,YZ could inhibit the apoptotic changes caused by A?(P