Abstract: A method of preparing Mo₂C via vacuum carbothermic reduction of MoS₂ in the temperature range of 1350-1550℃ was proposed. The effects of MoS₂-to-C molar ratio (α, α=1:1, 1:1.5, and 1:2.5) and reaction temperature (1350 to 1550℃) on the reaction were studied in detail. The phase transition, morphological evolution, and residual sulfur content of the products were analyzed by X-ray diffraction, field-emission scanning electron microscopy, and carbon-sulfur analysis, respectively. The results showed that the complete decomposition of MoS₂ under vacuum is difficult, whereas activated carbon can react with MoS₂ under vacuum to generate Mo₂C. Meanwhile, higher temperatures and the addition of more carbon accelerated the rate of carbothermic reduction reaction and further decreased the residual sulfur content. From the experimental results, the optimum molar ratio α was concluded to be 1:1.5.