Xylotrechus namanganensis is endemic to Middle Asia subregion of Palaearctic region. It causes severe damage to about 20 broadleaved tree species in the north of Xinjiang and greatly weakens the growth vigor of infected trees and even causes the host trees to die. X. namanganensis has one generation per year in the area of Kelamayi, and overwinters as mature larva in the trunk. The adult, larva and egg can be found at the same time from mid-April to mid-or late July, or even through a year. Three kinds of parasitoids were found, among which Leluthia sp. might be a new species, Aspidocolpus erythrogaster Tobias is a new recorded species in China, Zombrus sjostedti (Fahringer) is a new record species in Xinjiang. In addition, three parasitic fungi were found in the bodies of larvae, pupae and adults of X. namanganensis, namely Beauveria bassiana, Fusarium solani and Aspergillus candidus. none