Abstract: Nitrogen input and output in manure applications and grain yields from 1976 -1980 in Shuangbe No. 4 brigade are analysed and compared. The results show that the nitrogen consumption was higher than the nitrogen accumulation in the soil nitrogen balance ( -33.4%-+ 11.0% ), the ratio of organic manures and chemical fertilizers was obvious disorder (1.00:1.02) ; and the ratio of chemical fertilizer investment(unvaried price) in the total agrculture expenditures had increased by 2.5% every year. It is suggested that the nitrogen balance could be maintained by the plantation of green manure crops, proper application of manure and fertilizer and strengthening the nitrogen input into the farmland in the farmland eco-system, and so on. Only by raising the nitrogen utilization coefficient and the manure economic effect could the grain yield and farmer’s income be increased in the agricultural production.