The pyrolysis of biomass is one of the most promising renewable forms of future energy. The optimal parameters of pyrolysis and the proper equipment design require the knowledge of kinetics. In this paper, Thermogravimetric Analysis(TGA) was used to study the thermal degradation of rice straw at different heating rates (10、15、20、30℃/min) under a nitrogen atmosphere. The kinetic model for first order paralled linear reaction is provided and details are presented such as weight loss, temperature and kinetic data obtained during the pyrolysis of rice straw.