Abstract: In order to study the thermodynamic characteristics of coal samples oxidized in oxygen-poor atmosphere, thermogravimetric as well as differential scanning calorimetric experiments were carried out in the Laojunmiao sealed fire zone in Xinjiang under the conditions of 6%,12%,18%,and 21% of oxygen volume fraction. Combined with the changing law of TG curve to determine the critical temperature,dry cracking temperature,ignition temperature,maximum weight loss rate temperature and burn-out temperature,the coal oxidation process was divided into three stage,including weight loss by dehydration,weight gain by oxygen absorption and oxidation combustion,and finally the apparent activation energy of the three stages was calculated by CoatsRedfern method. The results show that the characteristic temperature points of the coal samples were shifted to the low-temperature region as the oxygen volume fraction increased from 6% to 21%. The heat release in the oxidizing combustion stage increased when the oxygen volume fraction increased,and the heat absorption and exothermic equilibrium point shifted to the low temperature. The exothermic rate at different oxygen volume fractions in the stable exothermic stage was positively correlated with the rate of weight loss,and the oxygen volume fraction had a greater influence on the thermal effect of coal in the stable exothermic stage when it was lower than 18%. The activation energy of the overall reaction process showed an increasing trend,and the activation energy of the oxidation and combustion stage was much larger than that of the other two stages. With the increase of the oxygen volume fraction, the average activation energy firstly increased and then decreased,and the average activation energy reached the maximum and the difference was not obvious when the oxygen volume fraction was 18%. The results of the study can provide basic theoretical support for the management of the sealed fire area in the Xinjiang coalfield.