Abstract: Field experiments and chemical components analysis were conducted to study the effects of different nitrogen application amounts on agronomic traits, yield and quality of flue-cured tobacco variety‘Xiangyan 5’, to provide a basis for large scale extension. The results showed that 135-142.5 kg/hm2 pure nitrogen could promote the normal growth of tobacco plants, form“medium tobacco plants”type and ensure leaf mature at moderate time. The flue-cured tobacco leaves had appropriate thickness with loose structure, medium identity, dense color, rich oil content and mainly in golden color. Different nitrogen application amounts affected tobacco economic factors, such as yield, output value, average price, and the proportion of upper- middle tobacco. T2 treatment (135 kg/hm2) had the best effects, compare with the control, the yield increased by 370.35 kg/hm2, 15.12 percentage, the output value increased by 12374.4 yuan/hm2, 21.82 percentage, the average price increased by 1.34 yuan/kg, 5.78 percentage, the percentage of upper tobacco leaf was raised by 6.01 percentage, and the sugar alkali ratio, nitrogen alkali ratio, and potassium chlorine ratio of flue-cured leaves were suitable, the internal chemical components of tobacco leaves were coordinated. Therefore, it is suggested that 135 kg/hm2 pure nitrogen should be the best rate in plating of flue- cured tobacco variety ‘Xiangyan 5’in southern Hunan tobacco area.