Abastract:In this study, the effect of the milling time on microstructure of Cu-0.5 wt.% Cr-1 wt.% Al 2 O 3 was investigated. The lattice parameter was evaluated by the X-ray diffraction technique. The microstructure was characterized by scanning electron microscopy. Also, size and distribution of Cr and Al 2 O 3 were investigated by using X-rays energy dispersive (EDX) mapping. The result shows that the lattice parameter of the Cu phase increases with increasing milling time. The changing trend of Cu particle sizes as the alloying time increases, the particle sizes first increase and then decrease. When milling 1.5h, the powders coarsen than as-received Cu powder. Then the particle sizes of the samples decreased when the milling time increased to 3h and above. In addition, the size and distribution of Cr and Al 2 O 3 decreased and dispersed much fine with increasing milling time.