Abstract: To investigate the vascular plant species composition and floristic characteristics of the Suibin Liangjiang Wetland Nature Reserve, a comprehensive plant diversity survey was conducted using a combination of transect-line and quadrat sampling methodologies. This study systematically compiled a vascular plant inventory for the reserve and employed fuzzy clustering analysis and principal component analysis to examine the floristic relationships between the Suibin Liangjiang Wetland and four adjacent wetland ecosystems. The results demonstrated that the reserve harbored 374 vascular plant taxa (including infraspecific units), distributed across 81 families and 234 genera. The angiosperms dominated the flora with 340 species (69 families, 214 genera), followed by pteridophytes (28 species, 11 families, 16 genera) and gymnosperms (6 species, 1 family, 4 genera). Notably, dominant families (27.16% of total families) comprising 261 species (69.79% of total species) across 155 genera (65.96% of total genera) constituted the principal components of the vascular plant community. Phytogeographical analysis revealed complex floristic elements in seed plants, with 5 family-level distribution types (plus 4 variants) and 10 generic-level distribution patterns (plus 11 variants). The seed plant flora exhibited distinct temperate characteristics. At the generic level, the floristic composition showed closest affinity with the wetland ecosystems of the Ashe River, the Hadong Riverside, and the Mayi River Delta. This investigation provided critical baseline data for implementing effective conservation strategies, scientific management protocols, and sustainable utilization practices of plant biodiversity in the Suibin Liangjiang Wetland Nature Reserve.