本文探讨了晒红烟主要化学成分在大田期积累变化规律，研究结果表明，总氮、蛋白质、总糖、还原糖的积累从移栽后３０天开始增加较多，烟碱是从移栽后５０天开始迅速增加。主要化学成分含量约５０％多是在移栽５０天以后积累。日积累出现最高值的日期，总氮是移栽后５０天，蛋白质是移栽后８０天，烟碱是６０天，总糖是７０天，还原糖是４０天。主要化学成分以叶中分布最多，茎次之，根最少；烟碱在根、茎、叶中的分布比例，生育前期和后期无明显的变化，而其它成分，生育前期以叶中分布居多，根、茎较少，到生育后期叶中分布逐渐减少，根、茎中的分布逐渐增加。 This paper discussed the accumulation and variation of main chemical components of sun-cured tobacco in the field. The results showed that the accumulation of total nitrogen, protein, total sugar and reducing sugar increased more from 30 days after transplanting, 50 days began to increase rapidly. About 50% of the main chemical composition is accumulated 50 days after transplanting. The date at which the highest accumulation occurred was observed with total nitrogen at 50 days after transplanting, protein at 80 days after transplanting, nicotine at 60 days, total sugar at 70 days and reducing sugar at 40 days. The main chemical components were most distributed in the leaves, followed by the stems and the least in the roots. There was no significant change in the distribution proportion of nicotine in the roots, stems and leaves, the early and late growth stages, while the other components mainly distributed in the leaves during the early growth period. Roots and stems less, to the distribution of late leaves gradually reduced, roots and stems in the distribution increased.