Abstract: In order to clarify the process of phosphorus transference in overlying water and sediment under different hydrodynamic conditions, changes of phosphorus concentrations in overlying water and sediment, biomass of submerged macrophytes and environmental factors were studied during the growth of Vallisneria natans and Hydrilla verticillata by indoor experiment. The results showed that submerged macrophytes could reduce the contents of various phosphorus fractions in overlying water during the growing period under hydrostatic(v=0 m/s) and hydrodynamic conditions(v=0.10 m/s), and total P (TP) contents in overlying water in hydrostatic experimental groups and hydrodynamic experimental groups ranged from 0.05 to 0.11mg/L and 0.02 to 0.17mg/L, respectively at the end of the experiment. In the hydrostatic experimental group, dissolved total P (DTP)contents were mainly decreased, while concentrations of DTP and particulate P (PP) were mainly decreased in the hydrodynamic experimental group. Compared with the control replicates, TP, inorganic P (IP) and NaOH-extracted P (NaOH-P) concentrations in the sediment of experimental groups were significantly decreased. At the end of the study, the sediment in the experimental group gradually changed from slightly polluted to unpolluted . There is a significant negative correlation between HCl-extracted P (HCl-P) and NaOH-P under hydrodynamic conditions.（Vallisneria natans group P<0.05; Hydrilla verticillate group P<0.01）.The biomass of submerged macrophytes increased rapidly (Vallisneria natans group 70~511g; Hydrilla verticillate group 30~510g) caused the increase of dissolved oxygen (DO) and pH in overlying water (hydrostatic experimental group DO 2.5~6.2mg/L, pH 7.3~9.3;  hydrodynamic experimental group DO 2.4~8.1 mg/L, pH 7.4~8.9), which indirectly affected the release of phosphorus from sediment to overlying water. Compared with Hydrilla verticillata, Vallisneria natans can effectively prevent phosphorus releasing from surface sediment. The results of this study supplemented the effects of submerging macrophytes on various phosphorus forms in overlying water and sediment under hydrodynamic conditions and provided a reference for the restoration of lakes and rivers by in situ phytoremediation.