In this paper, the combustion behavior of municipal solid waste (MSW) is carried out in a thermogravimetric analyzer under different N-2/O-2 and CO2/O-2 atmospheres with temperature ranging from 100 degrees C to 1000 degrees C. TG (thermogravimetric) and DIG (derivative thermogravimetric) curves are analyzed. The nth order reaction fitting model is used to yield the activation energy of reduction process according to the degree of conversion. The results indicate that all samples lose most their weight between 200 degrees C and 540 degrees C. As the oxygen concentration increased, conversion rate curves and DIG curves shift to lower temperature without significant change in its shape. At the same oxygen concentration, the peak values in CO2/O-2 atmosphere are smaller than those in N-2/O-2 atmosphere, indicating that CO2 has a higher inhibitory effect than N-2 on MSW combustion. After 600 degrees C, the weight loss peak appears much later in CO2/O-2 atmosphere than it does in N-2/O-2 atmosphere. With the increase of heating rate, the maximum weight loss rates of samples increase obviously. The three-step reaction of nth order reaction model fits the weight loss very well. (C) 2010 Elsevier Ltd. All rights reserved.