The effect of the compositional modulation and the structure near the layer boundary between ferromagnetic and nonmagnetic metals, on magnetoresistance (MR) in the Co/Ca and Co/Ag multilayers produced by pulse electrodeposition method has been investigated. It was possible to control the film thickness in the range of 4.5-39 Å by electrodeposition. From the experiments on the films with composition modulation near the layer boundary between ferromagnetic Co-rich layer and nonmagnetic Cu layer, it is observed that the MR ratio strongly depends on the thickness of the ferromagnetic layer rather than the change of the composition near the interface between magnetic and nonmagnetic layers.