Abstract: To investigate the moisture generation characteristics of tobacco materials under heating conditions, the pyrolysis behavior and the moisture generation trends by selected tobacco materials (laminar and reconstituted tobacco materials) and six components (cellulose, hemicellulose model compound, pectin, starch, glucose, fructose) were comparatively studied by thermogravimetric-mass spectrometry and heating furnace-Karl Fischer coulometry. The amounts of moisture generated by tobacco samples at different temperature ranges were quantified. The results showed that: 1) The initial temperatures for fructose pyrolysis and dehydration were about 35-45 ℃ lower than those for glucose. The temperature ranges of pyrolysis and dehydration of the hemicellulose model compound were wider than those of cellulose. Pectin showed a 30-40 ℃ lower initial temperature for pyrolysis and dehydration compared to starch. 2) Tobacco materials could continuously generate moisture during heating. There were three separate pyrolytic moisture peaks for the flue-cured tobacco sample in the ranges of 150-255, 255-335 and 335-390 ℃. The flue-cured tobacco sample had additional thermogravimetric and moisture release peaks at 160-235 ℃ compared to the burley tobacco sample. The fluctuation characteristics of the derivative thermogravimetric curve and moisture release curve for the rolling processed reconstituted tobacco material at 200-330 ℃ were both milder. 3) The proportions of moisture generated by the tobacco samples at 100-280 ℃ to the total amount of moisture generated at 30-280 ℃ reached up to about 50%. The amounts of moisture generated by the flue-cured tobacco and oriental tobacco at 100-280 ℃ first increased, then decreased and increased again; that by the burley tobacco showed an increasing trend followed by a steady stage at 100-220 ℃ and an increasing trend followed by a decreasing trend at 220-280 ℃; and that by rolling processed reconstituted tobacco exhibited a decreasing trend followed by an increasing trend at 100-220 ℃ and a gentle fluctuation trend at 220-280 ℃.