Abstract: To reveal the spatial pattern of plant species diversity in the inundation and resettlement region of the Three Gorges Reservoir, 129 plots were investigated along 14 sample belts. The sample belts were located at different aspects on both sides of Yangtze River, within the counties of Xietan, Wushan, Fengjie, Wanzhou, Fuling and Chongqing as well as the dam area. The investigated plots in each sample belt were taken at altitude intervals of approximately 50 m within an altitude range of 70–610 m above sea level. The spatial pattern along the altitude gradient was firstly examined by adopting the number of species and the Shannon-Wiener index based on coverage as species diversity indices. Secondly, DCCA (Detrended Canoni-cal Correspondence Analysis) was used to illustrate the relationship among environmental variables and spe-cies diversity indices to explore factors involved with spatial patterns of species diversity. The results indi-cated that the species diversity was higher on the southern side of Yangtze River than on the northern side. Species diversity increased but not so evidently with an increase of altitude. There was no evident correlation found between stream position (upstream or downstream) and species diversity, however it was found that the belts with the highest species diversity were located in the dam area and Wanzhou, while the lowest were in Chongqing and Wushan. DCCA revealed that the environmental variables most affecting species diversity was firstly the southern or northern location on the Yangtze River and secondly altitude. DCCA also revealed that the coverage of the canopy layer positively affected the species diversity, but the coverage of shrub layer affected it negatively. This suggests that the species diversity was determined by the characteristics of com-munity structure, especially the coverage of the arbor layer. It was concluded that the relationships between the spatial pattern of species diversity and environmental factors were altered by human disturbances, which are long-term and heterogeneous in space and intensity. The species diversity of the disturbed community was determined by characteristics of community structure, especially the coverage of the canopy layer.