The characteristics of oxygen-enriched air combustion of raw municipal solid waste (MSW) were studied by thermogravimetric analysis. Experiments on oxidative pyrolysis of MSW were carried out under different atmospheres (N2, N2:O2 =7:3, N2:O2 =5:5, N2:O2 =4:6, and N2:O2 =2:8) at 30°C/min. Two distinct peaks of weight loss were obtained according to the derivative thermogravimetric curves; one of them is centered on 305°C with about 40% weight loss, and the second is centered on 420°C with about 20% weight loss. Effects of oxygen concentration on the decomposition process and char combustion were analyzed, and then the process of oxygen-enriched air combustion of MSW was divided into four steps. Kinetic parameters were observed by direct non-linear regressions. According to the obtained data, the apparent activation energy and reaction order decreases along with the combustion process, while that of char combustion increases as oxygen concentration increases.