Abstract: Pot experiment was conduction to study the effect of organic N on the pigments metabolism and relating enzyme activity of growing flue-cured tobacco leaf. Results obtained are as follows: The content of Chlorophyll、Chlorophyllase、Carotenoids during the growth of flue-cured tobacco leaf under the organic N condition. Under the mineral N, the proportion of chlorophyll a/b were holding invariableness, but the proportion of chlorophyll a/b were lower during the later anaphase under the organic N condition. During the former and metaphase the content of neoxanthin under the organic N condition were more, but conditions were changed during the later anaphase. The content of lutein andβ-carotene in condition of organic N were remarked more than theirs in the mineral N condition. Two conditions had sameness effect on vioxanthin. During the former phase of flue-cured tobacco leaf the activity of LOX(mineral) were higher, but after 30 days the activity of LOX(organic) were remarkable higher than minerals. Proportion of the carotenoids and the relation of the pigment and relating enzyme had changed under the organic N. The experimentation indicated that chlorophyll and carotenoids had no remarkable relationship with the chlorophyllase and LOX during the growth of flue-cured tobacco leaf. This experimentation preliminary showed that β-carotene、neoxanthin were more were the one biochemistry reason of the aroma more under the organic N, and activity of LOX and chlorophyllase(under the organic)during the latter growth phase were the one physiology foundation of the better quality of flue-cured tobacco leaf under the organic N in Henan province.