Apoptosis is one form of cell death and many genes are involved in it.There is diferent signal transduction pathway during apoptosis.This article elaborates three signal transduction pathways mitochondria signal transduction pathway,death signal transduction pathway and endoplasmic recticulum signal transduction pathway.The comprehending of signal transduction pathway during apoptosis and their links will it easier to insight into the mechanism of apoptosis.All these will pave the step leading to our ultimate goat,which is to have cells die on genetic cue when they are not needed,and to rescue cells from death when they are wanted.