Abstract: The explosion limits of CBM(coal-bed methane) were determined with the temperature respectively at 20, 60, 100, 150, 200°C and pressure respectively at atmosphere pressure, 100, 200, 300 kPa by using the self-developed experimental setup. The results showed that with the increase of the initial temperature and pressure, the upper limit of explosion limits will increase, but the lower limit of explosion limit will decrease, resulting in expanding of the scope of explosion limits and increasing of the risk. The effect of initial pressure and temperature on the upper limit of explosion limits is more obvious than that of the lower limit of explosion limits. The results are helpful for the determination of safety process parameters of CBM.