Abstract: Diversity and floristic characteristics of aquatic seed plants of Henan Province in China are discussed in the paper.There are aquatic seed plants of 30 families,61 genera,125 species,1 subspecies,9 varieties and 2 forms in Henan Province,including emerged plants of 75 species,1 subspecies,5 varieties and 2 forms,floating plants of 33 species and 2 varieties,submerged plants of 17 species and 2 varieties.The pantropic,the north temperate and the old world tropical components are main components,followed by the East Asia and North America disjuncted and the old world temperate components.The proportions of the tropic and the total of all the temperate components are similar.