Abstract:The middle leaves of Yunyan87 were used as materials and processed imitating black tea method including withering(curing barn withering and film covered withering), rolling(20min), fermentation(6h) and drying(85-105℃two-stage method). Compared to conventional flue-cured tobacco with three-stage method, tobacco leaves prepared by imitating black tea method showed soft and subtle aroma, which was in moderate concentration, including sweet aroma, dry grass aroma, burnt aroma and baking aroma. GC-MS and LC-MS were used to test the chemical components of tobacco leaves, and the results showed that 2380 differential compounds were identified, accounting for 43.26% of the total compounds. Through principal component analysis(PCA) and hierarchical cluster analysis(HCA), it was found that there were significant differences in the content of compounds in tobacco leaves with two different curing methods. Withering method showed the biggest effect on smoking evaluation for tobacco samples prepared by imitating black tea method and plastic film covered withering showed better smoking quality. Drying method was important for the formation of characterized aroma. The correlation analysis showed that the contents of 2595 compounds were correlated with withering method. By orthogonal partial least squares discriminant analysis(OPLS-DA), 2708 marker compounds were identified and 757 marker compounds were identified by T-test and ploidy change. Through integration of the data with two different withering methods, 757 key differential compounds were identified.