Caspases are a group of enzymes mainly for the execution of apoptosis.In recent years,studies have shown that caspases participate in the occurrence and development of many diseases,especially tumors and nervous system diseases.Of those,caspase-9 is one of the most important initiating molecules.This article reviews the structural characteristics,activation and regulation of caspase-9,its regulation mechanism of apoptosis,and briefly describes its relation with ischemic cerebrovascular disease.