Based the modified cotton simulation model COTTON2K, comparison of growth and water use in thedifferent region: North China Plain and Xinjiang was done．The result showed that evapotranspiration ( ET) was 655mm for Shihezi in Xinjiang and 541
Yang Y, Ouyang Z, Yang Y, et al．Simulation of the effectof pruning and topping on cotton growth using COTTON2K model [J]．Field Crops Research, 2008, 106(2) : 126 － 137．
[4]
杨艳敏, 刘小京, 欧阳竹．棉花模拟模型 COTTON2000在新疆精准种植中的应用[J]．中国农业生态学报，2005, 13(3) : 123 － 126．mm for Yucheng in North China Plain．The yield in Shihezi is almost twice ofthat in Yucheng without water stress．At the same time, the relation between precipitation and ET were studied indifferent growth stages for the two areas．It showed that precipitation can satisfy 80% of water use for Yucheng, and21 % for Shihezi．Water use efficiency for Shihezi is higher than that in Yucheng．But cost of cotton production ishigher for Xinjiang due to its higher dependence on irrigation．
