A structurally toughened metal matrix composite reinforced by cast tungsten carbide particles (WC/W2CP) was fabricated by vacuum fusion sintering. Microstructure and properties of the particle-reinforced regions (WC/W2CP-NiCrBSi) in the composite reinforced by primary and modified WC/W2CP were investigated by SEM, EDS, microhardness testing and image analyzing. Effects of the surface-modified WC/W2CP on the wear behavior of the composite were estimated on a ring-disc wear tester at room temperature and 600 °C. The results show that the dissolution of surface-modified WC/W2CP is effectively restrained and the content of the residual WC/W2C eutectic in particle is 2.6 times of the primary WC/W2CP. The wear rate of the composite reinforced by modified WC/W2CP decreases significantly compared with the composite reinforced by primary WC/W2CP at room temperature and 600 °C. The laminated structure self-protecting layers are formed on the worn surface of the composite at 600 °C, resulting in a lower wear rate than that at room temperature.