Abstract: In order to study the products released during the process of thermogravimetric analysis(TGA) of a tobacco sample, a device for collecting TGA products was established. The tar-form product and five volatile carbonyl compounds(formaldehyde, acetaldehyde, acetone, acrolein and propanal) released at different thermogravimetric stages were collected, then analyzed by GC/MS and HPLC separately. The results showed that: 1) The pyrolysis process of tobacco samples could be divided into five stages, i.e. adsorbed water dissipation, volatile component evolution, bio-polymer thermal oxidative pyrolysis, coke combustion, and burnout stages. 2) At different thermogravimetric stages, the formation of tar-form products was obviously different; large amount of nicotine and a great number of aroma compounds formed at volatile component evolution stage; abundant tar-form products formed at bio-polymer thermal oxidative pyrolysis stage; and many aromatic compounds produced at coke combustion stage. 3) The volatile carbonyl compounds mainly formed at bio-polymer oxidative pyrolysis and coke combustion stages.