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Researching the effect of crop planting structure change on alteration of crop water demand and irrigation water consumption would provide basic data for irrigation water management in the period of crop growing and agricultural water resources planning. Based on the meteorological data of actual precipitation and evapotranspiration collected in Jinghuiqu Irrigation Area, the irrigation water requirement of main crops was calculated by using Penman—Monteith formula and crop coefficient method recommended by FAO, and the effective precipitations of rainy year (25%), normal precipitation year (50%) and draught year (75%) were determined through frequency calculation and fitting curve method. Then the total irrigation water requirement in typical hydrologic years was calculated according to agricultural crop planting structure data in different periods extracted from remote sensing images in Jinghuiqu Irrigation Area from 1998 to 2014. The monthly and yearly change of water demand of crop and irrigation water requirement of typical hydrologic years were analyzed. The results showed that, in Jinghuiqu Irrigation Area from 1988 to 2014, with the change of agricultural planting structure (the crop planting area was reduced by 63.5%, the orchard area was increased by more than 10.2 times, and the inhabitants area was increased by 1.63 times), the crop water demand and irrigation water requirement displayed a significant decrease. The total water demand was decreased from 780 million m3, 800 million m3 and 820 million m3 to 520 million m3, 530 million m3 and 540 million m3, and the amount of irrigation water was dropped from 290 million m3, 350 million m3 and 430 million m3 to 190 million m3, 230 million m3 and 270 million m3 in three hydrologic years, respectively. Among different planting crops, the ratio of amount of irrigation water consumption of winter wheat and summer maize was dropped from over 90% to 50%, while that of the orchard was grown from less than 5% to 50%, and that of facilitated agriculture tended to increase slightly. However, the average crop water demand of unit area of three hydrologic years from 1988 to 2005 was remained around 720mm, 700mm and 685mm, then it was decreased slightly, and later it was dropped to 700mm, 685mm and 670mm in 2014, during which period the average irrigation water requirement almost equaled to the average crop water demand of unit area. With the change of planting structure from 1988 to 2014, the total irrigation water requirement and total crop water demand of unit area in each month, apart from June, showed a significant decreasing tendency, but the average irrigation water requirement and average crop water demand of unit area were decreased in April, August and September, increased in June and remained the same in other months. It indicated that the decrease of crop water demand and irrigation water requirement was caused mainly by decrease of crop area, and slightly by change of crop structure. The result also showed that the crop irrigation water requirement after adjusted crop planting structure was more in accordance with the features of regional effective precipitation.