In order to study the improvement of cultivating techniques on water-cultivating vegetable such as waterconvolvulus(Ipomoea aquatica Forssr.), taro(Colocasia esculenta Schott), coba(Zizania caduciflora Hand), lotus(Nelumbo nucifera Gaerth )in northern area of Taiwan, these experiments were conduct in 1996. The result showed that using organic fertilizer will be better for the growth of taro and increase production, the best quality of taro are those which use No 1 organic fertilizer. The influence of coba production is flowing water better than stagnate water, the difference in the depth of water is not obvious, the crops in five-centimeter-deep stagnate water have the worst products. Waterconvolvulus sowed in drought land, propagated with cutting in water land, then harvest vegetable every 30 days; These varieties such as “Taoyuan no.1”, “Bai-gu”, “Ju-Ye” have up-right style and harvest easily, “Chin-gu” has stolen type and low yield. The most common insects on lotus are apple snail, army worm, small tussock moth and cotton aphid.
