This chapter discusses the electrical resistivity of AlxCu1-x. This short range ordering alloy has been investigated by electrical resistivity measurements after irradiation with electrons and neutrons and after quenching. SIA migration has not been identified; however, there is some speculation about a SIA migration temperature below 77 K as the irradiation had been performed at 77 K. The annealing stage near room temperature is attributed to vacancy migration. The superannealing of electrical resistivity indicates changes of the SRO. These changes have been established by diffuse X-ray scattering after n-irradiation. The influence of the alloy composition on the size of dislocation loops observed after n-irradiation has been investigated and a decrease in size has been observed for x>0.05, as compared to the dilute alloys. Change of electrical resistivity of AlCu alloy after different treatments is illustrated. Isochronal annealing of electrical resistivity for various composition of AlCu alloy is plotted after quenching from 500ºC.