Abstract: The thermal decomposition of bagasse in flowing nitrogen at 4 different heating rates was studied by TG. The apparent activation energy of thermal processing ranged from 102.40 kJ/mol to 161.24 kJ/mol was calculated by iso-conversional method. During the zone of activation energy was nearly constant, and the kinetic model function was 1/2 order simplex reaction, model function F0.5(α)=1-(1-α)1/2, the pre-exponential factor A is (5.991±0.947)×106 s-1.