Abstract: The plant diversity of Dongan Zishui national wetland park in Yongzhou, Hunan Province, was invested and analyzed by using two methods of the stand structure investigation and field reconnaissance. Based on the method of analytic hierarchy process (AHP), 4 indexes were selected, including the species richness, diversity of ecosystems, endemic and rare species and invasive species, and the evaluation system of plant diversity was constructed. The plant composition and dominant genera of  Dongan Zishui national wetland park were surveyed and counted. The results showed that ecological system type of  Dongan Zishui national wetland park was various and highly stable and plant resources were abundant. There were 1100 vascular plant species belonging to 195 families, 676 genera. Among them, 92 pteridophytes species were belonged to 31 families, 56 genera; 16 gymnosperm species belonging to 7 families, 13 genera, and 992 angiosperm species belonging to 157 families, 607 genera were discovered. The angiosperms was the most important plant type in  Dongan Zishui national wetland park. Agrostidoideae, Compositae, Faboideae and Rosaceae were identified as the dominant families. Plant diversity index was scored to 76.92, and the evaluation results was perfect.