Abstract: In order to study the coal partical affected to the coal oxidation reaction and activated energy, a programmed temperature rising experiment device of the coal spontaneous combustion was applied to study the oxygen consumption rate of different partical coal samples at the low temperature oxidation stage as well as the corresponding relationship between the gas product and temperature and to analyze the gas product and oxygen consumption rate with the temperature variation law. A critical temperature point of the different partical coal samples were obtained,the temperature point was used to divide the low temperature oxidation stage into two stages, and the kinetic analysis was carried out for different stages.Arrhenius equation between the oxygen consumption rate and coal temperature was established and the activated energy equation was obtained from the logarithmic processing. The linear regressive straight line slope of the equation was analyzed and the low temperature oxidized apparent activation energy of the coal sample was calculated. The study results showed that the partical size would have a high influence to the apparent activation energy. The larger the partical size was, the higher activation energy would be. The coal samples with the partical size of 5～7 mm would have maximum activation energy before the critical temperature reached. Compared with other particle sizes, the coal samples with the partical size would be not easy to have the spontaneous combustion at the low temperature stage. The comparison between the activation energy of the mixed samples showed that the spontaneous combustion tendency of No. 2-2 seam would be lower than No.3-1 seam.