AbstractCarbon dioxide molecules are preferentially adsorbed on coal surface, which reduces adsorbing oxygen and inhibits process of coal-oxygen adsorption. Through carrying out temperature-programmed experiment, inhibiting effect of carbon dioxide on process of coal-oxygen adsorption was studied, concentration values of O2, CO and CH4 produced by coal samples under different concentrations of carbon dioxide were measured, and law of concentration of carbon dioxide affecting consuming rate of oxygen and producing rate of carbon monoxide was analyzed. Results show that 37%-50% concentration of carbon dioxide has obvious inhibiting effect on oxygen consuming rate in process of coal's oxidation, and can reduce producing rate of carbon monoxide and methane obviously, which indicate that carbon dioxide can effectively inhibit process of coal-oxygen adsorption and prevent spontaneous combustion of coal. Experimental results could guide the development and application of fire preventing technology relating to carbon dioxide.