This study aimed to investigate the effects of straw returning and water-nitrogen management on nitrogen utilization of rice and soil physicochemical properties. Three factors split plot experiment was set up in the typical sandy loam area of rice-rape rotation in the Western Sichuan Plain: the main plot were two straw returning ways(composted straw and direct straw returning); the split plot were two ways of irrigation(flooded irrigation and aerobic irrigation); and the split-split plot were four N application rates(0, 75, 150, 225 kg/hm2). The results showed that straw returning and water and N management had significant interaction on N accumulation in rice at main growth stage, N translocation and utilization at filling stage(heading and maturity stage), rice yield and urease activity, mass fractions of ammonium and nitrate N of surface soil(0-20 cm) at maturity stage. The effects of composted straw returning on N utilization, yield of rice and soil physicochemical properties were significantly higher than those of direct straw returning. Under the same water-nitrogen management, compared with direct straw returning treatments, the N accumulation of plants and grains increased by 9.7%-32.9% and 7.5%-45.3%, respectively, the yields of rice increased by 7.3%-18.5%, and the average soil urease activities increased by 4.8%-9.7% of each growth period in composted straw returning treatments. Under the same straw returning and N application rate treatments, aerobic irrigation could increase the yields and N apparent use efficiency to different degrees, and increase the N agronomic use efficiency, soil ammonium and nitrate N mass fractions and urease activities of most treatments compared with flooded irrigation treatments. Within the same straw returning and irrigation methods, with the increase of N application rates, the N apparent and agronomic use efficiencies, yield, N accumulations of each organ(except for mature spike in 2017) and plant of rice, and the rice stem- sheath N translocation amount and efficiency, contribution rate, soil urease activity and nitrate N mass fraction from heading to maturation stages of rice increased first, these indexes were the highest when the N application rate was 150 kg/hm2, and then these indexes decreased over the N application rate increase. Under the conditions of this study, the combined management mode of composted rape straw returning, aerobic irrigation and combined application of 150 kg/hm2 N fertilizer could effectively enhance soil urease activity, N accumulation and N translocation amount and efficiency of stem-sheath during filling stage, which promoted the simultaneous improvement of high yield and N use efficiency.