Abstract: Fe-based amorphous alloy coating was fabricated on A3 steel substrate by air plasma spraying technology.The coating consists of amorphous phase and a few crystallized quenching cores which size is about 2~5 μm,little oxide has been found in the coating.The coating is formed by high-deformed bond-type particles heaping up each other and has laminar structure.The particles' deforming from spherical (the size is about 60 μm) to bond-type(the thickness is about 6 μm) ensures the amorphous alloy coating's forming.A few pores and tiny spherical particles exist at the boundary of bond-type particles in the coating.The adherence between coating and substrate and the coherence of coating are mechanical combination,and the interface between coating and substrate is the weakest zone.