Abstract: Sacada sp. is a main forest pest insect in our country, feeding on the leaves of Chinese fir. It is a new record insect species in our country, and was first found to damage the Chinese fir in Shanshui County in 1989, the area infested was above 500 hm². From 1989 to 1992,the morphology, bionomics and control technique of Sacada sp. were studied. The efficient control method was presented by the authors.