Suppression subtractive hybridization technology has been widely applied in the mechanism research of plant defense disease and insect pest,especially for fungi,bacteria and nematodes.The overall condition of ESTs from suppression subtractive hybridization libraries for plant resistance to disease and insect pest were generalized,and some highly expressed genes such as resistance genes,defense genes and signal transaction genes were analyzed emphatically.Finally,the future of SSH technology were reviewed.These helps to understand the universal rule of the mechanism of plant defense disease and insect pest,and enhance the application of suppression subtractive hybridization technology.