Abstract: In order to study the influence of the soaking time on the ability of coal low temperature oxidation, two series of experiments for five groups of coal samples which collected at Luning Mine were done under the constant temperature of 50 ℃ and 30 ℃ to 180 ℃. We studied the influence of soaking time on the standard oxygen consumption rate of coal, the generated rate of CO and CO₂. The results show that, with the increase of soaking time, low temperature oxidation ability of coal will be enhanced before falling, and there is a soaking time which is most likely to promote the ability of coal low temperature oxidation. Regardless of soaking time length, the oxidizability of soaking coal is stronger than the raw coal when the temperature exceeds to 155 ℃.