The contents of various aroma components and flavor quality in flue-cured tobacco leaves after irrigating root with soymilk in west Henan Province were studied. The results showed that soymilk root irrigation increased the total amount and quality of aroma components in middle and lower leaves, with the effects from high to low as middle leaves＞upper leaves＞lower leaves, and increased contents of benzeneacetaldehyde, acetyl-furan, 6-methyl-2-Heptanoicketone, 6-methyl-5-hepten-2-one, 2,4-glutric valeraldehyde-2, linalool, 1,3,3-trimethylcyclhex-1-ene-4-carboxa-ldehyde, β-damascone. The increased content of aroma components mainly resulted from products of brown reaction, cembratriendiol and carotenoids.