In order to investigate the pyrolysis characteristics and mechanism of moso bamboo, its pyrolysis behaviour has been investigated by thermo-gravimetric analysis (TGA), which can be described as four steps: dehydration, hemicellulose pyrolysis, pyrolysis of cellulose and lignin, and residue decomposition. The decomposition of hemicellulose, cellulose and lignin are the main contributions for pyrolysis weight loss. Furthermore, the pyrolysis mechanism has been clarified based on pyrolysis kinetics model fitting. Detailedly, the pyrolysis kinetics of hemicellulose agrees with first order chemical reaction, whereas the pyrolysis kinetic equation of cellulose and lignin accords with the 1D-diffusion parabolic curve. And the apparent activation energy of them is 124.62 and 232.64 KJ/mol, respectively.