Abstract: In order to understand the current status of vascular plant resources in Guangxi Sishuihe Regional Nature Reserve,a survey on the diversity of vascular plants in the reserve was conducted using a combination of comprehensive investigation,line transect and quadrat survey,and the species composition and floristic characteristics were analyzed. The results showed that there were a total of 1022 vascular plant species belonging to 634 genera and 184 families in the Sishuihe Nature Reserve,including 81 fern species belonging to 58 genera and 31 families,and 941 seed plant species belonging to 576 genera and 153 families. The composition of vascular plant families is dominated by families with few species and single-species families,accounting for 83.15% of the total number of vascular plant families. There were 15 species of national key protected wild plants and 10 species of invasive alien plants. The floristic composition of vascular plants in the Sishuihe Nature Reserve is rich and complex in geographic elements,with tropical distribution families and genera being dominant,indicating a significant tropical nature of the plant flora in the Sishuihe Nature Reserve,reflecting the characteristics of the floristic geographic composition in the southern edge zone of the South Asian tropical plants.