Abstract: An experimental study has been made to investigate the coal spontaneous combustion process of the coal sample in the 8132 working face of Yangquan No.5 Coal Mine. The relationship between coal temperature and precipitable laws of CO, alkane gas (C₂H₆, C₃H₈) and olefinic alkyne gas (C₂H₄,C₂H₂) is obtained during the natural oxidation process of the coal sample. The results show that the concentration of CO tends to increase significantly when the coal temperature reaches 180 ℃, the variation pattern of which presents the exponential form, however, the relationship is uncertainty between the concentrations of C₂H₆ and C₃H₈ and the coal temperature change. C₂H₄ can be detected when the coal temperature rises to 65 ℃, the relationship is still inapparent although the concentration rises with coal temperature rise. C₂H₂ occurs when the coal temperature approaches 130 ℃, the concentration increases dramatically along with the coal temperature increment whereas a sudden drop phenomenon appears if the coal temperature increases to 250 ℃.