Abstract: The nutrient uptake kinetics of M.aquaticum and E.crassipes were investigated by using the modified de-pletion method under nutrient solution of antimicrobial treatment and non-antimicrobial treatment.The maximum up-take rate(Imax) and Michaelis-Menten constant(Km) were estimated by iterative curve fitting.The Imax and Km for the plants was significantly different between two plants.The absorption rates of and in E.crassipes were significantly higher than that in M.aquaticum,illuminated that M.aquaticum was proper for treatment of the seriously polluted water.The Imax and 1/Km for was higher than that of in E.crassipes.In contrast,The Imax and 1/Km for was higher than that of in M.aquaticum.In E.crassipes,the absorption rates of in an timicrobial treatment were significantly higher than that in non-antimicrobial treatment,and the absorption rates of in antimicrobial treatment were significantly lower than that in non-antimicrobial treatment when the concentra tion of was higher than 1.00 mmol/L.There were no difference between antimicrobial treatment and non-antimicrobial treatment for the absorption rates of and in M.aquaticum.