Abstract: To study the impact of periodic water level adjustments on the characteristics of plant community in the hydro-fluctuation belt of the Three Gorges Reservoir, Zhong to Zigui section were selected for research. The plant species composition, distribution characteristics of life form and species diversity at different elevations were analyzed using important values and diversity indices. The results showed that: (1) There were 73 species in 32 families and 70 genera in the study area. Poaceae, Asteraceae, and Leguminosae were 3 dominant families, and the single species and genera were obvious. Cynodon dactylon, Xanthium sibiricum, Bidens Pilosa, Abutilon theophrasti, Eclipta prostrata, Polygonum lapathifolium, Alternanthera sessilis were co-existing species at three elevations. Among them, Cynodon dactylon and Xanthium sibiricum were dominant species at three elevations. (2) A total of 11 plant life forms were determined in the study area. In the lower and middle parts of the hydro-fluctuation belt, annual herbaceous plants occupied a great dominant position; in the upper parts, perennial herbaceous plants became dominant life form, and the plant life forms were more diverse. Ferns, vines, shrubs, and trees were beginning to appear. (3) The richness, diversity, and evenness index of the plant community in the hydro-fluctuation belt showed significant differences with changes in altitude, and showed an upward trend with increasing altitude. Therefore, the change of water level had a great impact on the plant community structure and species diversity. In the low-altitude section, the species composition was simplified, and plants with strong flood tolerance and reproduction ability became dominant species. The flooding stress weakened as the altitude rose, and more plant species that adapt to changes in water level appeared, causing plant communities to form different distribution characteristics along altitude changes. These results are of reference value for the selection of ecological restoration plants and the improvement of species diversity in the water-level fluctuation zone of the Three Gorges Reservoir.