Abstract: 【Objective】To investigate the impact of irrigation water quotas and calculation methods on the irrigation water use coefficient in the arid regions of Xinjiang.【Methods】Seven agricultural irrigation districts in Changji Hui Autonomous Prefecture in northern Xinjiang were selected as the input and target output systems,with the loam soil irrigation district in Changji（northern Xinjiang） and the aeolian sandy soil irrigation district in Hotan（southern Xinjiang） as representative cases,and an input-output model and field irrigation water tests was employed to monitor soil moisture in field irrigation.【Results】The marginal positive effects of input factors on the irrigation water use coefficient were ranked as follows：the proportion of micro-irrigation area>anti-seepage canals>well irrigation water volume>gross water consumption,indicating that expanding the scale of high-efficiency water-saving irrigation,anti-seepage of water conveyance canals,water-saving construction for well pumping irrigation significantly enhanced irrigation efficiency;when the field water use coefficient reached 0.70,the suitable moist layer depth for different irrigation methods in the irrigation districts ranged from 70 to 86 cm,accurately reflecting the effectiveness of irrigation water use;a method for calculating the irrigation water use coefficient that based on a constant net irrigation water quota was improved.【Conclusion】The expansion of the scale of high-efficiency water-saving irrigation,anti-seepage of water conveyance canals,water-saving construction for well pumping irrigation positively contribute to improving irrigation water resource use efficiency in the arid regions of Xinjiang. Notably,a suitable moist layer depth for the net irrigation water quota ranges from 70 to 86 cm.

Key words: The arid regions of Xinjiang, Irrigation district water resources, Irrigation water use coefficient, Calculation method improvement