Abstract: Co_0.36Cu_0.64 alloy nanowire arrays were prepared by electrodeposition inside the anodic aluminum oxide template and subsequently annealed at different temperatures.The as-deposited samples show single phase of fcc structure.The phase trainsition with heat treatment was investigated by x-ray diffraction which confirmed the phase departure of Co and Cu.This departure of the Co and Cu with the increase of the annealing temperature improved the coercivity of the nanowires by forming singe Co cluster in nanowires.