Abstract: The soil type is one of the major ecological factors affecting Wannan flue-cured tobacco sweet coke. An experiment was conducted to study the difference on antioxidant capacity and the relation with sweet coke of flue-cured tobacco middle leaf in different soil types in Anhui Wannan tobacco area. The results showed that: the content of MDA, TAOC of different age middle leaf were higher in flood loam and alluvial loam, but lower in paddy soil. For silt, the content of TAOC was higher, while the MDA and chlorophyll were lower, indicating that the oxidative stress for flue-cured tobacco growth in silt was stronger than the other 3 kinds of soil. The content of carotenoids and total phenolics in silt, flood loam and alluvial loam were higher than that in paddy soil, that may be the reason the coke sweet was better than in paddy soil; Moderate oxidative stress is conducive to the formation of tobacco-style sweet coke.