The kinetics of the thermal decomposition reaction of methyl ethyl ketone peroxide (MEKPO) with sulfuric acid of different concentration had been studied by an Accelerating Rate Calorimeter (ARC). The curves of the rate of temperature rise and pressure versus temperature of these reactions were attained. Following thermal decomposition kinetics, the apparent activation energy (E_a) and the preexpontial factor (A) of the decomposition reaction of MEKPO and its mixture with sulfuric acid were obtained by analyzing the ARC data. From the curves of the rate of temperature rise and pressure versus temperature,along with the kinetic parameters,the effects of 1% and 3% sulfuric acid on the decomposition reaction of MEKPO were analyzed.