Abstract: The vegetation in the hydro-fluctuation belt of Three Gorges Reservoir area as an important component of ecological system plays an important role in ensuring reservoir safety and social-economic development. The spatial distribution configuration and dominant plant species composition of the hydro-fluctuation belt are important bases for the selection of plant materials. Based on vegetation survey from four monitoring plots located in Zigui and Wushan, the trunk line of Three Gorges Reservoir, the species diversity, plant life form and spatial distribution configuration of dominant plants were investigated. The results are as follows. 1.With the altitude lowering, the species diversity decreased, the proportion of therophyte herbs increased, the species diversity of perennial herbs differed (in Zigui decreased, while in Wushan increased), and the species diversity of woody plant decreased. 2.The dominant species in deep water sections of Three Gorges Reservoir area mainly belongs to Poaceae, Cyperaceae and Asteraceae, such as Cyperus rotundus, Cynodon dactylon, Digitaria ciliaris, Setaira viridis, Bidens pilosa and so on. The dominant species survived in shallow water sections also mainly belongs to Poaceae and Asteraceae, but also emerged some new important value higher dominant species compared to deep water sections. The mechanism of these survival species is that they mainly have underground creeping rhizomes, well developed aerenchyma and strong adaptability to flooding and extreme dry hot environment when the water level drops.