Nanocrystalline W powder and tungsten based W-Ni-Fe prealloyed powders were prepared by high-energy ball milling. The influences of: (i) milling media including cemented carbide balls (CCB) and tungsten alloy balls (TAB), (ii) rotational speed, (iii) ratio of ball to powder, and (iv) grinding time on powder characteristics were studied. The grain size, lattice deformation and morphology, of the component of particles after milled were analyzed by means of XRD, EDX and TEM. The results showed that nanocrystalline powders with size of 10nm to 80nm could be synthesized by high-energy ball milling. The percentage of nanocrystalline particles in the powders is up to 80%. The overall properties of the nanocrystalline powders prepared using the TAB milling medium was better than those prepared by CCB milling. During milling the morphology of the nanocrystalline powder evolves from spherical to granular.