Abstract: The effective utilization of water resources has been an urgent issue to be addressed. According to the composition of agricultural ecosystem, factors affecting the efficiency of agricultural water use can be categorized into natural condition (climate, water resources condition and soil texture), type and size of the irrigation area, crop growth structure, engineering measures and irrigation technology, infrastructure and water saving configuration in the irrigation area, management level, economic policy and water price, etc. The influence mechanisms of these factors are different. Some are controllable, and some are hard to change. The mechanisms of these factors affecting the coefficient of effective utilization of farmland irrigation water are analyzed. Furthermore, measures to improve agricultural water use efficiency are put forward from aspects of facilities, regime, structure and technology.

Key words: agricultural ecology, water use efficiency, coefficient of effective utilization of farmland irrigation water, influence factor, mechanism