Coating　containing　amorphous　phase　on　a　mild　steel　substrate　was　prepared　by　arc　spraying　using　Fe-based　cored　wire　as　spraying　material,　and　then　the　coating　was　annealed　at　600　°C　for　1h　for　crystallization　of　the　coating.　The　microstructure　and　properties　of　the　coating　was　investigated　by　means　of　XRD,　differential　thermal　analysis,　transmission　electron　microscopy　and　wear　test.　The　results　show　that　the　coating　exhibits　the　typical　lamellar　structure　with　little　pores.　The　grain　size　of　the　coating　is　10~40　nm.　Microhardness　of　the　coating　is　about　1143　HV0.1,　and　the　wear　resistance　of　the　nano-coating　is　five　times　better　than　that　of　3Cr13　coating.