AbstractBased on the types of threatened species put forward by International Union for Conservation of Nature and Natural Resources( IUCN) , the threatened aquatic higher plant species of China were classified into seven types as follows : two extinct ( Ex) , sixteen endangered ( E) , thirty one vulnerable (V) , twenty two rare (R) , forty four indeterminate ( I) , twenty one out of danger (O) and eleven external ( El) species. The factors affecting these threatened species were also discussed.