In addition, it was found that NH4+-N concentration decreased by the effect of water spinach floating bed, the average removal rate of NH4+-N could achieve 60%. At the end of experimental period , which was in late August, the average concentration of NH4+-N was just 0.5 mg/L. However, there was little effect of NO3−-N removal by water spinach floating bed. The average NO3−-N concentration in the selected river during our experimental period was 1.24 mg/L . Moreover, the remarkable removal effect on NO2−-N from aquacultural drainage river by water spinach floating bed was observed except on 31st August. The average NO2−-N concentration in the selected river during our experimental period was 0.6 mg/L, which was reduced by 60.2%. The higher NO2−-N concentration might be because of the large scale of drainage and release of wastewater in aquacultural ponds in late August.