By thermogravimetric analysis (TGA), the influences of different catalysts on the ignition and combustion of municipal solid waste (MSW) have been investigated in this paper. MSW combustion can be divided into two steps. One is the emission and combustion of volatiles, and the second is the combustion of char. The existence of catalysts in the first step enhances the emission of volatiles from the MSW. When the concentration of volatiles around the MSW is high enough, the MSW ignites. The action of catalysts in the second step of MSW combustion may be as a carrier of oxygen to the MSW char. Two indices have been used to compare the characters of ignition and combustion of MSW under different catalysts. One is the temperature when the rate of conversion of the MSW is at 5%, while the other is the combustion when the temperature is at 850℃ in the TGA system. By comparing the different values of the two indices, the different influences of the catalysts on the ignition and combustion of MSW have been studied.