The FeCoCu/Cu multilayer granular films were prepared by the electrochemical deposition technique, and the effect of the L-ascorbic acid molarity on their structural, magnetic, and magnetoresistance properties was investigated. The structure of multilayer granular films is a face-centered cubic at room temperature, and the crystallite size increases from 5 to 14 nm with increasing the molarity of the L-ascorbic acid in the electrolyte. The recorded current-time curves indicate that 0.06 M L-ascorbic acid causes high current (200 mA) in the deposition of the magnetic layer during the electrochemical deposition process. The compositional analysis indicates that Fe deposition amount increases with increasing the L-ascorbic acid for the 0.04 and 0.06 M. The saturation magnetization decreases in the thin films due to increasing the molarity of L-ascorbic acid in the electrolyte. However, some of the Co and Fe reduces as a form of their oxide in the multilayer granular films containing a high amount of magnetic materials, and the antiferromagnetic behavior suppresses the ferromagnetic behavior. The multilayer granular film produced from the electrolyte with 0.04 M L-ascorbic acid exhibits both high magnetoresistance as 12% and 3.5% anisotropic magnetoresistance effect, and also, about 1 nm particle size.