In this study, we analyzed the beta diversity pattern of forest plant communities in Baishanzu Nature Reserve by typical quadrat methods. The beta diversity pattern was described by Chao's index based on 45 20m×20m plots in this area. Correlations between the beta diversity and five environmental factors (coverage of tree layer, elevation, slope grade, slope aspect and slope position) and spatial distances of communities were examined by Mantel test, Distance-based Redundancy analysis and ANOVA. The results showed that, beta diversity increased with spatial distance and environmental difference among plots, but only 36% of its variance can be explained by the joint effects of spatial distance and environmental difference. Specifically, only coverage of tree layer and elevation of the local community significantly affected on beta diversity at Baishanzu Nature Reserve. The impact of coverage of tree layer (explained 20.0% variance of the beta diversity) on beta diversity was also slightly larger than that of elevation (18.0%), and evidently lager than spatial distance (only 9.0%). Our study revealed the pattern of beta diversity and its relationship with environment and spatial distance of plant communities in Baishanzu Nature Reserve, and the results supported the joint effect hypothesis of habitat heterogeneity and dispersal limitation on beta diversity.