Abstract: In order to understand the pyrolysis and combustion properties and the release of volatile phase products from cigar tobacco leaves, the weight loss and evolved gaseous products of cigar tobacco leaves pyrolyzed in nitrogen and air atmospheres were studied by thermogravimetric analyzer combined with Fourier Infrared Spectrometer (TG-FTIR). The reaction activation energy in the different atmospheres was calculated with Flynn-Wall-Ozawa method. The results showed that: 1) The pyrolysis and combustion of cigar tobacco leaves had four weight loss stages: dehydration, pyrolysis of hemicellulose, pyrolysis of cellulose, pyrolysis and carbonization of lignin. Cigar tobacco leaves reacted violently in the air atmosphere with a comprehensive combustion characteristic index of 7.15×10^-8 %²·min^-2·K^-3. 2) The main gaseous components of thermal decomposition of cigar tobacco leaves were similar in nitrogen and air atmospheres, including H₂O, CO₂, CO and CH₄ as well as organic volatile substances, such as aldehydes, ketones, acids, alcohols, phenols and aromatic compounds; and the trend of gas/volatile releases was consistent with the thermogravimetric curve. 3) The pyrolysis process of cigar tobacco leaves was more complicated than flue-cured tobacco leaves for cigarettes. The activation energy of pyrolysis process ranged from 207 to 301 kJ·mol^-1, and the activation energy of combustion process was from 200 to 595 kJ·mol^-1. With the increase of conversion rate, the activation energy increased first, then decreased and increased again.