In low temperature oxidation experiment, coal can produce oxidation gas products, some of which can be used as the indicator gases. An understanding of the change rule of these gases can effectively forecast the spontaneous combustion in mined-out area. Through the comparison between the fresh coal samples and the oxidized coal samples in the coal seam of 7128 workface in Longdong Coal Mine in low temperature oxidation experiment, the gaseous products of fresh coal samples and those of oxidized coal samples are measured in different temperatures. Results show that the oxidized coal samples are the continuation of fresh coal samples, and both of them can produce such oxidizing gases as CO,CO2,CH4,C3H8,C2H4,C2H6,C2H2,C4H10 ,iC4H10, but the temperatures of the gases produced are different. In addition, when the temperature reaches 70 ℃, CO can be used as the indicator gases and C2H4 as the auxiliary index gases to serve as the early prediction of coal spontaneous combustion in 7# coal seam. Both the increase trend and the critical value of indicator gases can be adopted to forecast the mined-out area of coal oxidation conditions. In order to prevent the coal from spontaneous combustion, the research on coal’s low temperature oxidation experiment will monitor the temperature in mine-out areas.