In order to explore the community status of small mammals in Dongting Lake area after the Three Gorges Project, the small mammals in the marshland habitat of Dongting Lake area were investigated. From 2010 to 2018, the diversity of small animal communities in the marshland habitat of Dongting Lake area was investigated by snap traps, and the dominance concentration index, community diversity index and evenness index were calculated. The diversity index was compared by t value method, and the capture rate and rodent species composition of each year and habitat were tested by Chi-square test. The results of investigation as follow. From 2010 to 2018, a total of 34 116 traps were placed, 2 129 samples of distinguishable species were captured. Rodentia and Soricomorpha were the main species of small mammals captured in Dongting Lake beach habitat, including 7 species, Microtus fortis, Apodemus agrarius, Rattus norvegicus, Micromys minutes, Niviventer confucianus, R. losea and Suncus murinus. The total capture rate is 6.36%, among them, the capture rate of Microtus fortis and A. agrarius was higher, was 1.83% and 3.94% respectively (Table 1). From the composition of small mammals species in Dongting Lake beach, the dominant species are A. agrarius and Microtus fortis, and their proportion in the community is 63.18% and 29.26% respectively (Table 2). Among the five types of habitats investigated, the diversity index (1.077 2) and evenness index (0.666 2) of the small animal community in the habitats mainly composed of Carex sp. + Miscanthus sp. + Populus deltoides were the largest. It was followed by habitats dominated by Carex sp. (diversity index 0.927 5 and evenness index 0.572 3); habitats dominated by Miscanthus sacchariflorus (diversity index 0.885 6 and evenness index 0.550 2); and habitats dominated by Carex sp. + Miscanthus sp. (diversity index 0.775 6 and evenness index 0.481 9). The diversity index (0.323 6) and evenness index (0.180 6) of the habitat dominated by P. deltoides was the lowest, but the dominance concentration index was the highest (0.881 2) (Table 6). The results showed that with the operation of the Three Gorges Project, the vegetation succession in Dongting Lake area changed, which caused the dynamic change of the small mammal community. On the marshland of Dongting Lake, the more complex the habitat, the higher the diversity of small mammal species. In the single habitat, the greater the interference of human activities, the lower the diversity of small animal species. At present, the A. agrarius has become the first dominant rodent species in the marshland habitat of Dongting Lake.