Abstract: W-15%Cu alloys were sintered with mechanically activated powder in order to develop new preparing processes and improve properties of the alloys. The microstructures of activated powder and sintered alloys were observedand its properties such as density were measured. The results show that through mechanical activation, the surface energy and deformation energy of particles increase, and sintering processes were improved. Conglomeration microstructures in the alloys appear, W particles were sintered between each other mainly by way of solid sintering in the conglomerations, and liquid sintering between conglomeration and conglomeration. Microstructure of sintered alloys is compact and homogeneous. The relative density of the alloys is bigger than 98%. W and Cu are well-touched within the micromter scale, and some dissolving happened between the phases.