Searching for breeding in the system, 2-3 species of fish ,and 3-4 species can effectively control the water quality of horticultural crops.That use the system established last year.The change of Water quality about vegetables(Convoevueus、Leaf Mustard、Leaf Lettuce and Garden Lettuce)are NH4+ 0.025ppm-0.068ppm、TN 0.464-1.312、TP 1.5-18.6。The change of Water quality about fishes(Sea bass、Tilapia and Largemouth bass)are NH4+ 0.15ppm-0.21ppm、TN 0.32-0.81 ppm、TP 0.01-0.11 ppm。