Abstract: Effects of Ipomoea aquatica cultivation on artificial floating rafts on water quality of intensive aquaculture ponds were studied using total phosphorus (TP), total nitrogen (TN), orthophosphate phosphorus (PO₄^3--P), nitrate nitrogen (NO₃^--N), nitrite nitrogen (NO₂^--N), ammonium nitrogen (NH₄⁺-N), COD_Mn and chlorophyll-a (Chl a) as main water quality indexes,and its mechanism of purifying the water was explored in an experiment. Results show that the yield of Ipomoea aquatica, harvested four times,r eached as high as 69 618.0～73 161.6 kg·hm^-2. In Treatments 10% and 20% (refers to coverage of the pond by Ipomoea aquatica) 27.51 and 52.35 kg·hm^-2 of TN and 2.83 and 5.39 kg·hm^-2 of TP were, respectively, removed with the harvest of Ipomoea aquatica. In terms of the water quality indexes, Chl a, TN, NH₄⁺-N, NO₂^--N, NO₃^--N, TP, PO₄^3--P, and COD_Mn, the three treatments followed a decreasing order of CK > Treatment 10% > Treatment 20%.And the removal rate of Chl a, TN, NH₄⁺-N, NO₂^--N, NO₃^--N, TP, PO₄^3--P, and COD_Mn in Treatment 20% varied in the range from 15.16% to 49.02%,from 9.04% to 36.56%, from 19.23% to 46.34%,from 22.76% to 47.74%,from 13.33% to 56.52%,from 33.33% to 45.10%, from 27.27% to 48.15%, and from 3.13% to 19.05%, respectively. Fish survival rates in the treatments improved significantly as is compared with that in the control. So it was obvious that in ponds rearing fries of crucians,bighead carps and grass carps, cultivating Ipomoea aquatica on artificial floating rafts could accelerate water material cycling and strengthen self-purification capability of the water body.And it is advisable to set coverage of the pond by Ipomoea aquatica at 20%.

Key words: cultivating on artificial floating raft, Ipomoea aquatica, pond culture, environmental effect