Abstract: 【Objective】Understanding the differences in the decomposition of aquatic plants and water quality under different dissolved-oxygen levels plays an important role in plant residue management and water-quality control. 【Method】A eutrophic aquatic environment was simulated using a plastic box with Pistia stratiotes under conditions of non-inflated aeration(NA)and inflated aeration(IA).Under indoor and low-light conditions, water-quality indices were determined at different time points. Changes in the major water-quality indices during the decomposition of Pistia stratiotes were analyzed.【Result】Plant residue decomposed faster in the IA group than the NA group; however, the water-quality indices changed synchronously. The major water-quality indices in the initial decomposition stage(1-25 d)changed considerably, and was relatively stable in the subsequent stages(26-95 d).In the initial stage, the concentrations of NO^-₃-N and NO^-₂-N remained significantly higher in the IA group than the NA group, and the concentration of PO^3-₄-P remained lower in the IA group than the NA group; in the subsequent stages,in addition to NH⁺₄-N, values of the major indices were lower in the IA group than the NA group. In the IA group,the major water-quality indices reached maximum values simultaneously among different biomass levels. In the NA group, there was a delay in attaining maximum concentrations of NO^-₃-N, NO^-₂-N, and PO^3-₄-P,and the period of delay increased as the initial amount of plant biomass increased, particularly observable in variation in PO^3-₄-P concentration.【Conclusion】Generally, comparing with the effect of plant biomass, inflated aeration had a greater impact on water quality. Under the IA condition, the values of the major water-quality indices were higher than those in the NA group. There were significant differences in water quality between the two groups,especially at the initial stage of the study; however,at subsequent stages,the influence of inflated aeration on water quality indices was relatively small.