Abstarct: Since the first observation of giant magnetoresistance (GMR) in magnetic thin films, these films have attracted interest of many researchers, because of their potential in fabrication of magnetic sensors and hard disk heads. In this project, thin films of Cu1-xCox alloys were grown by electrodeposition method. At the beginning, potentiodynamic behavior of the ions in the electrolyte were investigated individually and also in presence of each others. This investigation determined the deposition voltages of the copper and cobalt, more negative than -0.4V and -0.95V (Vs. SCE), respectively. Moreover, the voltages should not be more than -1.2V, because of increment of side reactions, in addition to increment of mass and thickness calculation error, which were not desired. The results of Atomic Absorption Spectroscopy (AAS) showed that cobalt percentage in composition of deposited films increases as deposition voltage become more negative. In addition, when copper ion concentration in electrolyte decreased, the cobalt percentage of the films increased and the opposite occurred when agitation used during the deposition process. X-Ray Diffraction (XRD) patterns of the films confirmed all the films have fcc structure and by using the peaks profile, the grains size were calculated which was in range of 20-30 nm. Field Emission Scanning Electron Microscope (FESEM) images of sample’s surface showed non-spherical grains with inhomogeneous size distribution and average dimensions of 130nm. Magnetic measurement by Alternating Gradient Force Magnetometer (AGFM) revealed hysteresis loop at room temperature for all samples which imply they are ferromagnetic. It was observed that saturation magnetism increases and coercive force decreases as the cobalt percentage increases. Moreover, decrease of the film thickness resulted in more rectangular shape hysteresis loop. Finally, the effect of addition of sodium saccharin on surface roughness were studied by FESEM which these images showed Surface smoothness increases as sodium saccharin content in electrolyte increases. The reduction of average grain size from 130nm to 70 nm was observed for sample prepared in electrolyte which included 0.02M sodium saccharin compared with electrolyte without it.