Abstract: According to modern coal chemical structure theory,this paper summed up the change rules of activity chemical structures in coal surface during low-temperature oxidation of coal.The results showed that the oxidation reaction happened firstly on the spontaneous combustion characteristic structures in coal surface,such as methyl,methylene,hydroxyl,carbonyl,ether and other structures in the bridge bond and the side chain,which expressed as aliphatic hydrocarbon side chain and functional groups and oxygen groups increasing firstly and then decreasing,accompanied by the continuous generation of heat for coal spontaneous combustion system which laid the foundation for coal-oxygen sustained reacting.So,the quantity and the activity of spontaneous combustion characteristic structures in coal surface played an important role in low-temperature oxidation of coal.