Abstract: The structure and diversity are the important indexes of forestry ecosystem stability. During a systematic investigation in bamboo forest ecosystem from 2005 to 2007, 42～439 arthropod samples were obtained, which includes 511 species from 126 families of 17 orders. Lepidoptera insects occupied the largest number of species in the community, followed by Coleoptera and Diptera. The result indicated that, the community diversity of arthropod followed a obvious seasonal change pattern. The parameters of community composition, diversity and dominant concentration decreased in winter and summer when temperature was not suitable, representing double peaks with the season change. The peaks were in June and September separately. Based on the analysis of the functional groups, phytophagous group was predominant with species and population, followed by the natural enemy group, and neutral group was the least. In phytophagous group, the predominant species were not clear, and mosquitoes, Anopheles sinensis and Aedes spp. were predominant significantly in neutral group. In the group of natural enemies, predators including spiders and predacious insects were dominant.