Zizania latifolia is profitable for nutrients uptake and nutrient elimination from enclosed system, serving as food for migrating swans. Experiments in the laboratory scale were conducted to evaluate the inorganic nitrogen uptake by Zizania latifolia with the changing inorganic nitrogen concentration and its ratio. In order to eliminate the effects of soil adsorption, experiments were carried out on water culture. The highest rate of inorganic nitrogen (ITN) uptake was obtained when the NH₄-N and NO₃-N concentrations were the same in November. The uptake rate of NH₄-N by Zizania latifolia was higher than that of NO₃-N. It was also known that the uptake rate of ITN during April and July was higher than that of ITN during August and November. The highest rate of NH₄-N uptake was acquired when initial NH₄-N concentration was 21mg·l^-1. But, when the initial NH₄-N concentration was 28mg·l^-1, the rate of NH₄-N uptake was declined. The relationship between ITN concentrations and the rate of ITN uptake was obtained as the following: Y=1.03X⁄(6.8+X)