Abstract: Thirty-four samples of different grade tobacco leaves collected from different areas were expanded by dry-ice individually, the aroma components in the expanded cut tobacco were extracted by direct solvent extraction. The aroma components in cut tobacco were determined by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry before and after expansion. The influence of expansion on the contents of aroma components in tobacco was statistically analyzed. The results showed that: 1) After expansion, the contents of some aroma components, such as 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one, furfural, 5-hydroxymethylfurfural, 3-oxo-α-ionol and scopoletin, decreased significantly, while the contents of myristic acid, oleic acid, stearic acid and geranylacetone increased significantly. The contents of solanone and megastigmatrienone did not change significantly. 2) The different variation trends of those aroma components resulted in the drop of sensory quality of expanded cut tobacco.