Abstract: Through the field investigation,collecting the specimens and reviewing the relevant literatures,the list of seed plants in Chayu Nature Reserve was sorted out. On this basis,the plant species composition and floristic elements of the area were analyzed. The results showed that there were 1 231 seed plants in the protected area,belonging to 116 families of 497 genus. In the floristic elements,the composition of the tropical nature was dominant,accounting for 55.72% of the total number,especially in the pan-tropics. At the genus level,the temperate elements were dominant,the number of 43.27%,followed by tropical distribution. There were 448 monotypic genus and oligotypic genus in the flora,accounting for 90.14% of the total genus,accounting for the absolute superiority,and the degree of differentiation was very high. Protected areas flora geographical elements was complex,with a certain degree of transition and a certain proportion of the unique ingredients.

Key words: Chayu Nature Reserve, seed plants, flora