Abstract: To investigate coating powdering resistance of galvannealed steel, coating thickness, coating Fe content, coaling Al content and coating phase distribution of different galvannealed high strength IF steels were investigated with glow discharge spectrometer (GDS-750A), X-ray diffraction (XRD) and scanning electron microscope (SEM-S4200). It was indicated that for the investigated galvannealed high strength IF steel when the coating thickness was high and the coating Al content was low, the coating powdering quantity was larger. It was also indicated that when the surface coating and sub-surface coating were mainly composed of loose δ1 phase, the coating powdering resistance was much better than that of coating with almost all of compact particulate δ1 phase in the surface coating.