Abstract: By investigating vascular plant species composition and association characteristics of Jiangsu Huai'an Baima Lake National Wetland Park, this study aims to provide fundamental data and scientific bases for the biodiversity conservation of this Ramsar Site. A systematic survey based on transect and quadrat methods was conducted in the wetland park in the summer of 2022 and the spring of 2023. Based on this survey data, plant association types were clustered using Two-Way Indicator Species Analysis (TWINSPAN), and then their diversity indices were calculated. The park hosted a total of 232 species of wild vascular plants from 161 genera and 69 families. Eight dominant families accounted for 50.86% of the total number of species; genera with one-species-record accounted for half of the pool. The numbers of herbaceous, typical woody and woody lianas were 201, 28, and 3, respectively; there were 176 mesophytes, 28 hydrophytes and 28 hygrophytes. Cosmopolitan type was the major floral component at the family level, whereas temperate areal type was the major component at both genus and species levels. In spring, there were 16 major associations, and Ass. Geranium carolinianum had the highest species abundance while Ass. Vicia sativa had the highest species diversity indices. Ass. Zizania latifolia + Myriophyllum verticillatum was the most widely distributed. In summer, there were 12 major plant associations, and Ass. Alternanthera philoxeroides + Echinochloa crusgalli had the highest species abundance while Ass. Spirodela polyrhiza + Lemna minor had the highest species diversity indices. Ass. Typha angustifolia + Phragmites australis was the most widely distributed. Jiangsu Huai'an Baima Lake National Wetland Park is rich in vascular plant species diversity, but has a relatively high proportion of invasive species and a low proportion of hydrophytes and hygrophytes. The plant association types are also diverse, and significantly varied between seasons.