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The aim was to study absorption and utilization of nitrogen fertilizer of maize under different water and fertilizer conditions by using the 15N tracer technique. Three irrigation levels (200m3/hm2, 400m3/hm2 and 600m3/hm2) and five nitrogen application levels (0kg/hm2, 150kg/hm2, 200kg/hm2, 250kg/hm2 and 300kg/hm2) were set. The absorption of nitrogen from fertilizer and soil in different organs of maize was studied at maturation stage. Soil nitrogen excitation effect and nitrogen fertilizer efficiency under different water and fertilizer conditions were also studied. The results showed that the nitrogen absorbed from fertilizer by maize accounted for 33.32%~43.54% and the nitrogen absorbed from soil by maize accounted for 56.46%~66.68% under different water and fertilizer conditions. It was showed that soil was the main nitrogen source of maize growth. The different organs’ competitive ability to nitrogen from fertilizer was different, and the expression in a descending trend was grain, leaf and stem. Increasing of nitrogen application could improve the absorption ability of maize to nitrogen from soil, but it was necessary to increase the amount of water when excessive nitrogen was applied, in order to make the maize absorb more nitrogen from soil. The 15N residue in 0~60cm soil layer was increased with the increase of nitrogen application rate. With the increase of irrigation volume, the residual amount of 15N on the surface was decreased. When the amount of irrigation was 400m3/hm2 and nitrogen applied was 250kg/hm2, the yield reached 14063.04kg/hm2, and the soil nitrogen reservoir was in equilibrium state which not only achieved high production, but also met the needs of environment friendly. The conclusion can provide reference for the management of corn fertilizer and water and the sustainable development of agriculture.