In order to investigate the effects of submerged plants on the exchangeable nitrogen across the interfaces between sediments and water in eutrophic shallow lakes, the concentrations of NO^-₃-N and NH₃-N were detected with the continuous flow-injection analyzer through simulation experiments. With other environmental indicators taken into account, the effects of different densities of Potamogeton crispus L. (0 g, 150 g, and 300 g, respectively)on TN, NO^-₃-N, and NH₃-N at the sediment-water interface were examined. The experimental results show that Patamogeton crispus L. increased the oxidation-reduction potential(Eh)and decreased the pH of the interstitial water. Moreover, the higher the density of Patamogeton crispus L. was, the more significantly the Eh and pH in the interstitial water changed. According to the results of one-way analysis of variance, there was a significant difference(p<0. 05)in TN in the interstitial water with 0g and 300g of Patamogeton crispus L. The higher the density of Patamogeton crispus L. was, the greater the amounts of TN, NO^-₃-N, and NH₃-N in the interstitial water, and the greater the amounts of fixed ammonium, organic nitrogen, NH₃-N, and NO^-₃-N that were removed from surface sediments.