Abstract:The aim of current study was to reveal the utility of irrigation and rain water resources in paddy fields. Based on the observation of the field water balance in experimental plots with frequent and shallow irrigation (FI), wet-shallow irrigation (WI), controlled irrigation (CI) and rain-catching and controlled irrigation (RI) treatments, this study established the classification method of consumption fluxes of irrigation water and precipitation and the evaluation index system of utilization utility. The response of irrigation and drainage mode of water resources utilization was analyzed. The results showed that water consumption, effective utilization rate and water productivity were all affected by irrigation and drainage mode. In 2017-2018, the water resources consumption of all treatments varied in the range of 695.9~999.1 mm, among which the water resources consumption in CI treatment were the lowest, and the consumption structure was more reasonable. The irrigation water productivity (IWP, 5.392 kg/m3), the precipitation productivity (PWP, 1.539 kg/m3) and the water resources productivity (WRP, 1.364 kg/m3) in CI treatment all showed the highest water resources production capacity. The irrigation efficiency (IE), precipitation use rate (PE) and generalized water efficiency (GE) were 0.472, 0.406 and 0.693, respectively, which the differences among treatments were less than the differences among treatments about productivity indexes. The water resources utility evaluation index system based on the distinction between irrigation water and precipitation consumption flux could truly measure the performance of water resources in agricultural production, especially in the growing season with frequent precipitation. The results can provide theoretical basis for the evaluation of agricultural water resources utility and the formulation of paddy field irrigation and drainage mode.