A new WC matrix nanocomposite cermet was prepared by hot-press sintering. In the composite, certain amounts of VC is added to the composite as grain growth inhibitors. The consolidation is carried out under pressure 30～35Mpa and sintering temperature 1610°C for soaking 30min sintering. Microstructure of the nanocomposite cermet is scanned by SEM and mechanical properties are measured. It is detected that microstructure and fracture morphology is dissimilar to different particle sizes. Experimental results show that particle size of WC is important to the composite. Results show that relative density and hardness have the similar trend in growth. Meanwhile, the function of Al2O3 addition is also investigated in this paper.