The microstructures of ZrC particle reinforced tungsten matrix composite (ZrC P/W, 30vol%ZrC particles) have been investigated using XRD, SEM and TEM. The experimental results indicate that the ZrC particles inhabit the growth of tungsten grains during sintering. The relative density of the composite is less than that of monolithic tungsten. W atoms diffuse in the lattice of ZrC, resulting in a formation of (Zr, W)C solid solution in ZrC particles, and a little of Zr diffuse in W lattice, resulting in a metallurgical bonding of ZrC particles to W matrix. W 2C and ZrO 2 phases were found rarely in the composites. At room temperature, the fracture toughness, elastic modulus and hardness of the composite increase because of the additive ZrC particles, but the flexural strength of the composite is lower than that of monolithic tungsten. The toughening mechanisms of ZrC P/W composite are crack deflection and grain refining.