Abstract: In this paper, CaCl₂ solution was used as an inhibitor. Raw coal was soaked in CaCl₂ solution with a mass concentration of 20%, and inhibited coal samples were prepared at different temperature conditions (30 ℃, 50 ℃, 70 ℃ and 90 ℃) for different periods of time. The inhibition effect of CaCl₂ solution on coal spontaneous combustion was studied through temperature programmed tests and infrared spectrum experiments. It was found that the content of surface active groups (−CH₃, −CH₂, −COOH, −C=O) and coal oxygen consumption rate decreased significantly with the increase of pre-inhibition temperature and pre-inhibition time. The inhibition rate and cross point temperature also increase significantly. The results show that increasing the pre-inhibition temperature and the pre-inhibition time can obviously improve the inhibitory effects on the spontaneous combustion characteristics of coal.