A study of the vascular hydrophyte communities and biomass was undertaken in the Bigumdo wetlands, Shinangun, from March to November, 2005. As a result, the vegetation was divided into 14 communities. Among them, emergent hydrophytes consisted of 6 communities, including Miscanthus sacchariflorus community, Phragmites communis community, Typha angustata community, Leersia japonica community, Paspalum disticum var. indutum community, and Persicaria thunbergii community, floating hydrophytes 5 communities including Hydrocharis dubia community, Nelumbo nucifera community, Euryale ferox community, Trapa japonica community and Nymphaea tetragona var. angusta community, free-floating hydrophytes 2 commuinties including Lemna paucicostata community and Spirodela polyrhiza community, and submergent hydrophyte 1 community, including Myriophyllum verticillatum community. Biomass was the highest at emergent hydrophytes and decreased along the life form, in the order like floating hydrophytes, submergent hydrophyte and free-floating hydrophytes. In addition, hydrophytes in the Bigumdo wetland showed the typical vertical zonation pattern like a natural swamp. These results were considered that the wetland of Bigumdo was characterized by the typical structure of aquatic plant ecosystem.