In order to prevent spontaneous combustion prediction in Donghuantuo Coal Mine, temperature programmed gas chromatography experiment was used to test gas content in process of heating index, CO、CO2、CO /△O2、CnH2n+2 / CnH2n+2、CnH2n / CnH2n+2、CnHn / CnHn and so on were calculated. The result showed that CO could be detected in whole process of coal oxidation at low temperature, C2H4 could be detected after 140 ℃. Therefore, Co between 50 ℃ and 350 ℃ was selected as index, CO2、C2H6 and C3H8  were taken as auxiliary indexes. C2H4 between 140 ℃ and 300 ℃was selected as gas prediction index, Index gas of C2H4 / C2H6 and C2H4 / CH4 were taken as auxiliary sign gas in that range of temperature. Therefore, index gas was determined, which provided reference for spontaneous fire prevention in Donghuantuo coal seam.