This study had been performed to clarify the distribution of specific plants and hydrophytes in the 27 sites of drainage basins located in Youngsan River at the period of June 1997 to July 1999. Hydrophytes were composed of 32 familis 86 species and hygrophytes 36 familis 135 species. Among hydrophytes, emerged plant, floating-leaved plant, submerged plants and free floating hydrophytes were 52, 15, 12, and 7 species respectively in this investigation. Threatened species were Drosera rotundifolia, Utricularia racemosa, Utricularia bifida, Utricularia japonica, Hydrocharis dubia, Endangered species were Brasenia schreberi and Euryale ferox.