Abstract: In order to find out the key factors affecting the tobacco flavor classification, 3 types of flue-cured tobacco leaves in 6 tobacco planting areas in China were used as the research objects, and the objects were classified based on the random forest algorithm. The results showed that the correct rate made up 82.35% of the whole samples, in particular the correct rate for QING type reached 100%, but the correct rate for the other types did not match the reality perfectly. Meanwhile the importance of each variable could be reflected under random forest algorithm. In this case the key factors was as following: benzyl alcohol, β-ionone, 2-cyclopentene-1,4-dione, 2-acetyl-5-methyl-furan, methyl palmitate, 5 -(hydroxymethyl) furfural, 3-hydroxy-β-damascone, β-dihydro damascene, furfural, phenylethanol, dihydroactinidiolide etc. Therefore, the random forest algorithm could be applied to the study of tobacco flavor classification, achieve good result in the classification of overall flue-cured tobacco samples, and find out the key factors of classification. Therefore, the random forest algorithm could be explored in the tobacco research.