HVOF cermet coatings have been widely used to improve the wear resistance. In the present study, an abrasive wear model is proposed according to the examination of wear mechanism. The relation between the relative abrasive wear and the size and content of carbide particles in cermet coating is established. HVOF WC-Co and Cr3C2-25NiCr coatings are deposited to correlate experimentally the relation between the carbide particle size and abrasive wear. The microstructure of coatings is examined using scanning electron microscopy (SEM). The carbide particle size in the coatings is measured according to SEM images of the coating. It has been found that experimental results correlate with the theoretical model well. The abrasive wear of HVOF carbide cermet coating is determined by carbide size and content. The relative abrasive wear resistance will be increased with an increase in carbide content and the decrease of square root of relative carbide particle size.