Abstract: Ceramide as an important member of sphingolipid is a second messenger responsible for regulating cellular activities, whose major function is to transmit growth-inhibiting signals including apoptotic.It has been proven by a lot of experimental facts that the changes of the functions at different levels of ceramide signaling pathway directly affect cellular drug sensitivity and radiation sensitivity.In addition, the defective functions of ceramide signaling path in tumor cells may result in the decrease of their drug sensitivity and radiation sensitivity.