The study of nitrogen (N) balance in stock farming system is the basis of nutrient management in animal husbandry production, and the determination of N cycling parameters is the foundation of this study. Through documents checking and data collecting, this paper analyzed the items and values of input/output parameters of N cycling in stock farming system, and ascertained the estimation parameters of N balance in the system, which could offer the theoretical foundation for nutrient management in animal husbandry production.