Abstract: In order to provide fertilization guidance to flue-cured tobacco production in Liuyang, the optimal nitrogen application rate for flue-cured tobacco in Liuyang tobacco-rice rotation region was discussed by studying the effect of nitrogen application rate on agronomic traits and chemical components in tobacco leaves. The results showed that: (1) N 120 kg/hm2 could not meet the requirements of growth and development of tobacco plant, while the increase of N application rate could significantly improve the agronomic traits and dry matter accumulation; (2) there existed significant differences in economic traits among different treatments, the yield and output value of N 120 kg/hm2 treatment were significantly lower than those of N 150-210 kg/hm2 treatments, the rate of middle and high grade leaves and the average price of N 150 kg/hm2 treatment were the highest, and its coordination of yield and quality was better; (3) as for upper and lower leaves, the contents of total nitrogen and nicotine were relatively high in N 150 kg/hm2 treatment, and the coordination of chemical components was better; as for middle leaves, the contents of total nitrogen and nicotine were relatively high in N 180 kg/hm2 treatment. Comprehensively considering plant growth and development, yield and quality of tobacco leaves, 150 kg/hm2 was the optimal N rate for flue-cured tobacco in Liuyang tobacco-rice rotation region.