Abstract: In order to study the influence of the water’s pH on the ability of coal low temperature oxidation, the programmed heating experiments for five groups of coal samples which collected at Luning Mine were done by using the self-developed temperature-programmed experimental device;we detected the concentration of a variety of indicators of coal samples at the gas tank outlet under different conditions. By calculating the standard oxygen consumption rate, the change rule of CO and CO₂ generated rate and the methane concentration, we studied the influence of water’s pH on coal low temperature oxidation characteristics. The results show that, under different temperature conditions, the effect of water’s pH on the ability of coal low temperature oxidation is significantly different. When the temperature exceeds 160 ℃, neutral and acidic water environment can promote the coal oxidation ability. But alkaline water environment can partly reduce the coal oxidation ability when the temperature exceeds 55 ℃.