Abstract: According to the literatures concerned, the rare and endangered plants of Hainan Island consists of 57 species, 49 genera and 35 lamilies, which include..pteridophytes 1 species, 1 genera and 1 family; gymnospermae 10 species, 7 genera and 5 families; angiospermae 46 species, 41 genera and 29 families. Based on the analysis of the composition and the geographical elements, it indicates that the flora has the following features.-(1)The tropical composition shows the obvious advantages, and it occupies 80% of the total number of genera; (2)the rare and endangered plants show some characters of the interims, and some parts of genera have temperate zone features; (3)the flora of rare and endangered plants in Hainan Island has the association with the South China flora and the flora of China-India Peninsula. Finally, measures and proposals for protection are put forward for the rare and endangered plants in Hainan Island.