Abstract: In order to reduce nicotine content in upper leaves and determine suitable application nitrogen amount,the field experiments on effects of nitrogen amount on growth and development and yield and quality of TN90 were conducted.The results showed that the plant height,stem perimeter,leaf area per plant and yield increased as the increasing of the amount of applied nitrogen.Value of product,average price,rate of top qulity leaves were higher under preferential amount of applied nitrogen. Agoronomic character, economic character,Quality charater were considered comprehensively that the 270kg/ hm2 nitrogen applied was better.