Abstract: To provide a scientific basis for oats fertilizing in the farming-grazing transitional zone（FGTC） of China,the abundance-deficiency index（ADI） of soil N and the appropriate nitrogen application rates（ANAR） of different N abundance-deficiency level soil for oats in the FGTC of China.The method of regression equation between soil available nutrient content and relative yield of the treatment with complete nutrients except one,the improved scheme for the grading of soil available nutrients abundance-deficiency,and the new applied formula based on ＂nutrient balance and projected yield minus soil fertility yield＂ for determining the appropriate fertilizer application rates were employed.The results showed that the ADI of soil alkaline hydrolysis nitrogen for oats in the FGTC of China for the second to seventh level were≥248,161-250,105-161,69-105,45-69 and 45 mg/kg,respectively.The ADI of soil total nitrogen for oats in the FGTC of China for the second to eighth level were ≥2.9、2.0 -2.9、1.4 -2.0、1.0 -1.4、1.0-0.7、0.5-0.7 和 0.5 g/kg,respectively.When the nitrogen fertilizer use efficiency in current season is 40%,and the projected yield of oats is1.5-6.0 t/hm^2,the ranges of ANAR for the first to eighth level soil are 0-0,11-45,23-90,34-135,45-180,56-225,68-270 and 89-315 kg/hm^2,respectively.