Abstract: Fe-15Cr-3.5B-xC(x=0.1, 0.5, 1. 0wt.%) hardfacing alloys with different carbon contents were deposited by flux-cored wire using metal active gas arc welding (MAG). The effects of carbon contents on microstructure of the hardfacing alloy were analyzed by optical microscope, X-ray diffraction (XRD) and scanning electron microscopy(SEM). The macro hardness and wear resistance of hardfacing alloys were tested. The results indicate that Fe-15Cr-3.5B-xC hardfacing alloys consisted of MB, Fe B,M23(B,C)6，M3(B,C) and matrix, which contained ferrite , austenite and Fe-Cr solid solutions. With the increasing carbon content, the volume fraction of plate strip M2B decreases. Although the hardness of hardfacing alloys is improved, but wear resistance decreases. The main wear mechanism referred to furrows which caused by plastic deformation , brittle fracture and fall off of hard phase.