The flora, vegetation structure and physico-chemical characteristics of surface sediment were investigated in Paksil-nup wetland of Hapcheon-gun, Gyeongsangnam-do, Korea in 1990~1998. Ranges of the surface sediment characteristics such as pH, conductivity, organic matter, total nitrogen, available phosphorus, exchangeable K, exchangeable Ca, exchangeable Mg, and exchangeable Na were 4.36~4.34, $19.0{\sim}1260.0\;{\mu}mho\;cm^{-1}$, 0.01~6.35%, 0.001~0.14%, 0.01~0.31 mg/l00g, 1.01~13.98 ppm, 16.75~143.80 ppm, 0.93~14.85 ppm and 0.21~3.86 ppm, respectively. Percentages of the particle size such as sand, silt, and clay were 13.0~93.3%, 5.4~71.7%, and 0.5~37.5%, respectively. The flora of the study area was composed of 72 families, 182 genera, 223 species, 36 varieties and 2 form or total 261 kinds, and those were 45 kinds of vascular hydrophytes and 216 kinds of vascular hygrophytes. The life form of vascular hydrophytes was classified as 27 kinds (60%) of emergent plants, 8 kinds (18%) of submerged plants, 6 kinds (13%) of free-floating plants and 4 kinds (9%) of floating-leaved plants, respectively. The importance value of Salix nipponica was highest as 123.78 in the shrub and tree layers, and that of Trapa japonica was highest as 16.69 in the herb layer. The vegetation type was divided into two groups according to the association analysis. The vegetation of the littoral zone was classified into 7 associations according to the cluster analysis based on the coverage data. These results showed significant differences with those of stand ordination by correspondence analysis based on the species composition and by PCA based on the sediment properties. Factors affecting the distribution of the vascular hydrophytes and hygrophytes were the gradient of particle size, altitude, and water depth.