In order to clarify the potential of nitrogen(N) fertilizer reduction of typical single-cropping rice in Liaohe Delta，on the basis of understanding the status of regional fertilization，N supply and N loss risk were studied using a method combining the investigation of current situation of regional fertilization and in-situ field experiment in this study.The results showed that the amount of N fertilizer application varied in the range of 200～350 kg·hm-2 in the single-cropping rice region in Liaohe Delta and the regional average fertilization amount was 294.5 kg·hm-2 with the regional average economic yield of 10479.9 kg·hm-2.According to the N fertilizer requirement during rice growing，the recommended nitrogen application rate was 182～202 kg·hm-2. Under the condition of ensuring crop yield，suitable slow-release fertilizer reduced the application of nitrogen fertilizer by 19.2%～30.8%，increased the utilization rate of nitrogen fertilizer by 1.39%～15.79%，and maintained soil nutrient content.The nitrogen content in the surface water decreased by 68.4%～79.6%.And the economic benefit increased by 541.4～5816.6 yuan·hm-2.In summary，in regions with high nitrogen reduction potential，the replacement of chemical fertilizers with slow-release fertilizers under the condition of appropriately reducing nitrogen input can ensure crop yield and reduce the environmental risk of nitrogen loss with the reduction of labor cost and the improvement of economic benefits.