This study observed the treatment capacity of the CW with water hyacinth during a 40-d period in autumn. Its long-term capacity has not yet been studied. In future, water hyacinth will be replaced by Potamogeton crispus L. and grassleaf sweetflag rhizome (Rhizoma Acori Graminei) as the CW aquatic plants during spring and winter because the growth of water hyacinth stops if the temperature remains under 0°C for a period of 24 h. Another point is that the study planted only one type of wetland plant in the CW. Other studies, however, have reported that the integration of various plants enhances the CW treatment capacity (Martin et al., 1996).