Acorus calamus L, Yperus slternifolius, and Vetoveria zizanioides were planted in test floating beds. Three beds where the water flowed automatically due to the gravity were used in the research. The quality of the leakage water was checked. The results indicated the COD, TN and TP could be removed from the floating bed system of Acorus calamus L and the mixed floating bed system of Acorus calamus L and Yperus slternifolius, respectively. The data indicate that the direct absorption of nitrogen and phosphorus by the plants was not the major removal approach. When the inflow water quality was worse than V kinds of heavy polluted river water, the average elimination rate of COD, TP, TN in the floating bed of Acorus calamus L, Yperus slternifolius and Vetoveria zizanioides could reach 20.46％, 23.3％, 18.9％；38.35％, 45.46％, 44.8％, and 42.34％, 45.82％, 38.6％, respectively.