The kinetic parameters such as pre-exponential factor and activation energy of hemicellulose, cellulose, and lignin were well determined by the linear regressions of selected, sufficient thermogravimetric data, and close to literature values. The pyrolysis of biomass can be divided into four stages. There was only drying in the zeroth stage (<150 degrees C). In the first stage (150-250 degrees C), some light hydrocarbons were produced with the early pyrolysis of biomass. The biomass was mainly pyrolyzed in the second stage (250-500 degrees C) with higher reaction rates than those of other stages. The productions of H(2) and CO(2) in the third stage (>500 degrees C) may be able to be the evidence of self-gasification of char existing at higher temperatures. (C) 2010 Elsevier Ltd. All rights reserved.