Erosion and corrosion has been a long standing problem that leads to significant maintenance cost for many industries. Here, we report metallic glass as the novel material for erosion-corrosion resistance application. Metallic glass has gained technological interest due to its superior properties in high hardness, good strength and chemical resistance. Using an inert gas atomization process, we produce iron-based metallic glass powders with near spherical shape and amorphous structure. The powder is then cold spray coated onto metallic substrates to form amorphous coating. The coating is dense with microhardness of exceeding 1000Hv. The oxygen content is very low of 0.1 wt.%, significantly lower than that of other thermal spraying processes. The coating also shows high corrosion resistance, and its wear resistance is sixteen times higher than that of the uncoated substrate, suggesting the enhanced performance of the metallic glass as protective coating.