Abstract: In order to study the variation law of coal spontaneous combustion characteristics, the temperature programming experiment of coal spontaneous combu stion was used to research the characteristics of raw coal and pre- oxidized coals. The results showed that, compared with the raw coal, the oxygen consumption rate, CO and CO2 production rate, heat release intensity of pre- oxidized coal to 90 °Cwere higher with temperature increased. The variation curves of the oxygen consumpti on rate, CO production rate, heat release intensity of pre- oxidized coal to 130、170 。C with temperature increased had cross points temperature with that of raw coal. T he cross point temperature was 80 ~ 90。C to pre- oxidized coal to 130 °C and was 110 ~ 120。C to pre- oxidized coal to 170 °C. The above three parameters values of p re- oxidized coals were higher than that of raw coal when temperature was below the cross point temperature while they became smaller in opposite direction. The CO2 production rate of pre- oxidized coals to 130 °C and 170 °C was bigger than that of raw coal when the temperature was below 80 °C while it became smaller when the te mperature was over 80 °C. The minimum float coal thickness and lower limit oxygen concentration extremum of pre- oxidized coals decreased, and upper limit air- leaka ge intensity increased. With higher degree of oxidation, the variable quantity of critical parameters extremum was greater.