Abstract：This paper presents the experimental studies on the tendency of the spontaneous combustion of sulfide ore dump during early stage. It is shown that the oxygen concentration keeps almost unchanged in incubation period, development period and period near self-ignition, varying in a range of 17%~18%. In addition, the SO2 concentration can be identified only in the period near self-ignition. However, the temperature variation of sulfide ore dump, as an obvious indicator in the process from oxidization and self-heating to self-ignition, proves to be the best index for predicting the tendency of the spontaneous combustion of sulfide ore dump. Based on a few existing temperatures data, it is possible to predict the temperatures by means of the exponential curve method and the results of prediction show that the forecast model is very effective. As a result, this model can be used in the mining safety and security practice.