The WC－Co composite coating bonded strongly with steel matrix is made by vacuum fusion sintering (VFS). The constitution structure and the morphology of the composite coating are observed and analyzed by SEM, X-ray diffraction meter and micro-hardness instrument. A series of experiments on the cobalt based composite coatings of the different tungsten carbide percent are fulfilled by a pin-on-disc abrasion machine. The results show that the wear resistance of the cobalt based composite coatings are prior to that of the 45 hardened steel, and that the higher the tungsten carbide percent, the better the wear resistance; The wear resistance of the hardened steel decreases greatly whereas that of the composite coating varies slightly when the load increases.