The combustion of three different waste species and bituminous coal under N-2/O-2 and CO2/O-2 atmospheres was analysed using a Thermos gravimetric instrument. Under the same atmosphere, the combustion of three different waste species is different from coal. The major weight losses for coal, MSW, straw and sludge occur at 400-650 degrees C, 270-500 degrees C, 260-550 degrees C and 220-820 degrees C, respectively. The derivative thermos gravimetric (DTG) profiles of coal, MSW, straw and sludge shows one peak, four peaks, three peaks and two peaks, respectively. The atmosphere affects the burnout and the rate of weight loss of all the samples, while only the ignition temperature of coal and paper sludge is affected. On the whole, replacement of N-2 by CO2 influences combustion negatively, including less complete burnout (except for coal), lower maximum weight loss rate, and shift of small humps to higher temperatures (except for straw). Therefore, some improvement measures, such as an increase in oxygen concentration, are required under CO2/O-2 atmosphere to achieve the same combustion performances in air.