Abstract: In order to solve the serious spontaneous combustion problem of coal left in the goaf of No.121301 coal mining face in Kouzidong Mine, after the analys is on the low temperature oxidized test conducted in No. 121301 coal mining face, CO was provided to be the mark gas when the coal temperature was ranging from 30 to 100 °C. When the coal temperature was ranging from 100 to 140 °C, C2H4 was provided to be the mark gas. When the coal temperature was over 140 °C, C3H8 was provided as the mark gas and the fire disaster coefficient R2 as the auxiliary index parameter, the paper discussed the function relationship formula between the mark g as concentration and temperature. In the actual application of No.121301 coal mining face, the mass conservation was applied to indirectly calculate the concentration of the initial mark gas CO. With the buried pipe detection of C2H4 and C3H8, a method with the function relationship formula to calculate the environment temperature of the coal lft. The experiment results applied to the site practices would be excellent.