Abstract: Combined with vacuum sintering, W-20 % Cu/C composite material was prepared by mechanical alloying. Carbon nanotubes can be used as strengthening phase for W-20 % Cu composite material for its good overall performance. The particle sizes of W-20 % Cu composite powder and the density and hardness of W-Cu composite materials with different carbon nanotubes addition are analyzed by applying particle size tester. Adding carbon nanotubes can continuously refine the grain size of W-20 % Cu composite powder. The density and hardness of W-20 % Cu composite gradually increases with increasing mass fraction of carbon nanotubes. It shows that mechanical alloying technology enables carbon nanotubes dispersed in the W-20 % Cu composite, which leads to fine grain strengthening.