The electrodeposition of cobalt nanoparticles from mixture of 1-butyl-3- methylimidazolium chloride (BMIC) ionic liquid and urea was investigated. The results from the cyclic voltammetry (CV) show that the reduction of Co(II) to cobalt is an irreversible process and controlled by the diffusion of Co(II) on Pt working electrode. The cobalt nanoparticles prepared by direct current (DC) electrodeposition method at 70 °C were characterized by scanning electron microscope (SEM). Test results indicate that the Co nanoparticles are grain-like arrays and link together because of their magnetic property. The average length of these particles is about 100 nm.