Carbon thermal reduction reactions of manganese ore powder by microwave heating and conventional heating were investigated. The effects of temperature,particle size and carbon-oxygen ratio on the reduction rates by microwave heating were studied by thermogravimetric analyzer. Afterwards,the dynamic equation of the carbothermal reduction process was obtained by fitting regression,and the rate-increasing factor Q which characterized the rate increase of microwave heating with respect to conventional heating was obtained. The results showed that the material heating rate augmented with the increase of carbon-oxygen ratio,and the heating rate was performed rapidly at the initial stage and then gradually decreased by microwave heating. The increase of both temperature and carbon-oxygen ratio could accelerate the reaction rate. The reaction rate was also significantly increased with the reduction of ore particle diameter till 150 mesh. Moreover,the weight loss of reduction reaction by microwave heating was much larger than that by conventional heating under the same temperature and heat preservation time. It indicated that microwave heating performed evident effect on speeding up the reaction rate at the low temperature and late stage.