Abstract: The sulfidation rate constants of various Fe-Mo binary alloys in S₂ vapor with different sulfidation parameters were collected to summarize the correlation between the sulfidation rate and alloy composition, sulfur pressure and sulfldation temperature. The octivation energies indicate that the sulfidation process of the alloys is exclusively controlled, at a given temperature, by one alloying component i.e. either Mo or Fe. The sulfidation rate declines exponentially with the increasing of Mo content in alloy. And the influence of sulfur pressure is relatively slight.