Abstract:The aim is to explore the main influence mechanism in change process from regional to local scale. Based on plant investigation data of Baishanzu Nature Reserve and field investigation of the 5 hm2 plot in Baishanzu, the differences in species composition and functional traits at regional and local scales were compared. The results showed that there was significant difference between regional species pool and local community. Among top 10 families and genera of species number in Baishanzu Nature Reserve and plots, only 5 families and 5 genera were common. Compared to genera in whole Baishanzu Nature Reserve, temperate genera increase obviously in plots, and tropical genera were less. At aspect of functional traits, the ratios of herbal plants, compound leaf, bisexual flower or dry fruit in Bishanzu plots were lower than those in Baishanzu Natrure Reserve, while the ratios of woody plants, single leaf, unisexual flower and flesh fruit were higher in Baishanzu plots than those in Baishanzu Nature Reserve. These suggested that non-random processes, such as niche differentiation, play an important role in construction of local community.