Abstract:Small-scale physical experiment in the laboratory has been taken for simulating the effects of Paspalum distichum,Leersia hexandra, Hydrocotyle vulgaris, Ludwigia peploides and Iris pseudacorus on the literal-zone sediment stabilization by collecting sandy soil from lower reaches of Yangtze River and clay from the literal-zone. The results indicated that the reduced degree of porosity and increased proportion of specified particle (diameter <50 μm) of sediments could improve the quality of overlying water. The linear regression model of the improvement of sediment stabilization with five kinds of plant (Paspalum distichum,Leersia hexandra, Hydrocotyle vulgaris, Ludwigia peploides and Iris pseudacorus and fine root parameters (root length density, root surface area density and root weight density) is put forward. The correlations of root parameters of Leersia hexandra,Paspalum distichum, Hydrocotyle vulgaris with the degree of sediment porosity and with the particle diameter have positively linear correlations with slop arranging from 0.006 to 1.727, respectively, while the negative linear correlation of Iris pseudacorus, Ludwigia peploides with slop arranging from -0.091 to -0.011. Improvements of sediment porosity of Iris pseudacorus and Ludwigia peploides were attained to 15% and 9%, respectively, and improvement of particle diameters to 92% and 47%, respectively. The linear equation was used to calculate the plants' root parameter:11.495 and 9.475 cm/cm3 in root length density, 0.368 and 0.294 cm2/cm3 in root surface area density, 1.844 and 0.944 mg/cm3 in root weight density, for root parameters with sediment porosity and with the particle diameter, respectively. The sediment porosity improvements of Leersia hexandra, Paspalum distichum and Hydrocotyle vulgaris were attained to 6%,36% and 1%, and distribution of particle diameter improvement to 16%,17% and -13%, according to linear equation which was calculated with plants' root parameter:1.057, 7.368 and 0.651 cm/cm3 in root length density, 0.033, 0.228 and 0.022 cm2/cm3 in root surface area density, and 0.678, 2.537 and 0.160 mg/cm3 in root weight density, respectively. Five literal-zone plants are all proved to improve sediment stabilization, which repress eutrophication and sediment resuspension caused by soil erosion on lakeshore. Comparably, the effectiveness from high to low are in descending order from Leersia hexandra, Paspalum distichum, Iris pseudacorus, Ludwigia peploides to Hydrocotyle vulgaris.