Abstract: Changes of polyphenols in tobacco leaves during the flue-curing process and relation analysis with some chemical componets were studied. Leaf samples were taken from different tobacco producing regions of Henan Province. The results indicated that the content of total phenols increased during 0-24 hours of curing and then decreased. It reached the lowest point at 72 hours of curing and increased quickly after 72 hours of curing. The content of chlorogenic acid also showed the trend of raising during 0-24 hours of curing. But the lowest point tended at 24 or 36 hours of curing and then it slowly increased until curing process ended. The content of rutin generally increased with the proceeding of curing and showed little fluctuation; But the changes of PPO and POD activities were on the contrary. The highly significant positive correlations were observed between rutin and total sugar（r=0.822**）, and the significant negative correlations with starch, nicontine and protein, respectively.

Key words: tobacco leaf, flue-curing, total phenols, chlorogenic acid, rutin, chemical componets