[Objectives]  To determine the species, damage and population dynamics of longicorn beetles (Cerambycidae) infesting Rosaceous fruit trees (Rosaceae) in an orchard in Delisi township, Wafangdian city, Liaoning Province. [Methods]  Longicorn beetle larvae were reared in cages to adulthood and identified to the species level and the types of damage caused by different species was analyzed. [Results]  (1) Eight species were identified; Trichoferus campestris Faldermann, Glaphyra kojimai Matsushita, Pterolophia multinotata Pic, Stenygrinum quadrinotatum Bates, Aloe bungii Faldermann, Megopis sinica White, and Mesos myops Dalman. (2) Aromia bungii commonly infested the main stem of trees, whereas Mesosa myops, Chlorophorus diadema and Pterolophia multinotata mainly infested weakened stems and branches. Megopis sinica mainly infested rotten trees and Trichoferus campestri infested withered trunks and branches. Glaphyra kojimai and Stenygrinum quadrinotatum mainly damaged slender branches. (3) Trichoferus campestris, Glaphyra kojimai, Pterolophia multinotata, Stenygrinum quadrinotatum, Aromia bungii and Megopis sinica each had one annual peak of emergence but Mesosa myops had two and Chlorophorus diadema had no obvious peak period of abundance. [Conclusion]  The population dynamics of the eight species of beetle differed and different species infested different parts of fruit trees and caused differing degrees of damage to the health of infected trees. The most serious damage was caused by Aromia bungii.