为研究淹水稻田在排水条件下的氮肥流失规律，在上海青浦农田水利试验站进行了田间试验。试验资料分析表明，在淹水层中施肥后氮素（ＮＨ＋４ － Ｎ 或ＮＯ－３ － Ｎ）浓度衰减呈指数消退。在稻、麦连作田块，水稻生长期内，氮的挥发损失较大，而通过暗管排水流失的氮素占全部损失量比例较小。当控制沟水位及田面水层的水位差，合理控制稻田渗漏量时，可减少氮肥流失量 In order to study the law of nitrogen loss in submerged paddy fields under drainage conditions, a field experiment was conducted in Shanghai Qingpu farmland water conservancy experimental station. Experimental data analysis showed that the decline of nitrogen (NH 4 + -N or NO 3 - N) concentration exponentially declined after fertilization in the flooded layer. Nitrogen volatilization losses are greater during the growing season of paddy, wheat even fields and paddy rice, while the nitrogen loss through the underground pipe drainage accounts for a small proportion of the total loss. When the water level control surface and surface water level difference, a reasonable control of paddy leakage, nitrogen loss can be reduced