Abstract: The pattern of water consumption in three different ecosystems (forest fruit crops agroforestry system,forest fruit agroforestry system and cotton ecosystem) was studied by anayling the plant transpiration in Rudong city,Jiangsu province.The results were mainly as follows:although there were some differences in the transpiration rate of different plants,the daily and seasonal change courses of different plants were the same.The daily course of plant transpiration rate showed a pattern of single peak with a high value in midday and a low value in the early morning and early evening,respectively.The transpiration rate changed with the plant development and change of environment facts and showed a seasonal change pattern of low highlow.The plant transpiration rate was obviously affected by light intensity,relative humidity and air temperature.The forest fruit agroforestry system had the lowest water consumption and highest water usage efficiency in the three ecosystems and it proved to be one of the optimum cultivation patterns for higher economic benefit and effective uses of water resource in seacoast areas.