The Cu/Ni multilayers were deposited using ion beam sputtering at room temperature and250℃ respectively. The microstructures of the multilayers including intedecial roughness, grainsize and growth direction have been investigated by transmission electron microscopy and X-raydiffraction. The microstructure depends strongly on the substrate temperature and modulationwavelength, bigger grain size and larger intedecial roughness were obtained when the multilayerswere deposited at 250℃, and the multilayers ceased to grow epitaxially due to the increasingdefects in the multilayers. The resistivity of the multilayers is very sensitive to the microstructuredue to the size-effect. In order to study the influence of the microstructure to the resistivity，the in-plane resistivity of Cu/Ni multilayers was measured using fourpoint probe. The resistivityincreases with higher substrate temperature, and it decreases when the modulation wavelengthbecomes short. The interfacial roughness and grain size have co-contribution to the resistivity.The interface scattering is the main factor that has effect on the resistivity of Cu/Ni multilayers. The Cu / Ni multilayers were deposited using ion beam sputtering at room temperature and 250 ° C respectively. The microstructures of the multilayers include intederal roughness, grainsize and growth direction have been investigated by transmission electron microscopy and X-raydiffraction. The microstructure depends strongly on the substrate temperature and modulationwavelength, bigger grain size and larger intedecial roughness were obtained when the multilayerswere deposited at 250 ° C, and the multilayers ceased to grow epitaxially due to the increasing defenses in the multilayers. The resistivity of the multilayers is very sensitive to the microstructuredue to the size In-order to study the influence of the microstructure to the resistivity, the in-plane resistivity of Cu / Ni multilayers was measured using fourpoint probe. The resistivity of creases with higher substrate temperature, and it decreases when the modulation wavelength becomes short. The interfacial roughness and grain size have co-contribution to the resistivity. The interface scattering is the main factor that has effect on the resistivity of Cu / Ni multilayers.