Based on the spontaneous combustion coal ganguethose properties were studied including chemical compositionstructurephases and character by X-ray fluorescence spectrometer(XRF)thermogravimetry(TG) and differential scanning calorimetry(DSC)X-ray diffraction (XRD) analyzing by JADEelectron probe microanalysis(EPMA) and energy dispersive spectrometer(EDS) after selectingcrushingmilling and sieving.The results indicate that the phase of coal gangue from Tongchuan after spontaneous combusting are α quartzκ Al 2O 3amorphous SiO 2and -amorphous Al 2O 3mixing some calcite and dolomiteThe temperature of spontaneous combustion is in the range of -600-700 .In the process of spontaneous combustionthe amorphous body is formed morethe crystallization rate is lowerthe composition of elements is more dispersivewith the structure of spontaneous combustion coal gangue is destroyed worsethe activation properties are higher.