Abstract: A micro-crystalline aluminide coating of 100μm thick was obtained by vibratile electro-pulse deposition on Cr5Mo steel. An Fe-Al intermetallic compound layer forms due to high temperature during instant discharging between alumimum electrodes and specimens, micro-crystalline structure is achieved due to the high cooling rate during deposition, and the coating bonds with the substrate firmly. The experimential results of oxidation in air for 200h at 600 ℃ and sulfuration in flowing 99.98%SO₂ for 50h at 600 ℃ and the analysis of SEM and XRD show that the high temperature oxidation and sulfuration resistances of Cr5Mo steel with aluminide coating are greatly improved.