The microstructures and phase compositions of the WC reinforced Ni-based self-fluxing alloy composite coatings prepared by oxy-acetylene flame spray-welding were investigated with optics microscope（OM）and X-ray diffraction ( XRD) . The wear performance of the spray-welding coatings was tested by a MLS-225 wet sand rubber wheel abrasive wearing tester. The micrograph of the sprayed powders and the worn surfaces of the coatings were examined with scanning electron microscopy (SEM). The results have shown that the microstructures of the spray-welding coating are composed of γ-Ni solid solution，with large amounts of fine carbide grains such as Cr7C3，Cr23C6, Cr2B, CrB2 and WC particles. The hardness of the spray and fused Ni base WC composite coatings firstly increased and then decreased with the added content of WC，and the WC content for the highest hardness and abrasive resistance of coating is 25%.