Abstract: A cobalt nanoparticles modified ITO electrode (NpCo/ITO) was prepared by casting cobalt nanoparticles onto ITO electrode and the cobalt nanoparticles were synthesized by NaHB₄ reduction. The electrochemical behaviors of adriamycin (ADM) on NpCo/ITO were studied. The modified ITO electrode was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). In a 0.01 mol·L^-1 PBS (pH 8.0) buffer solution, a sensitive reduction peak of ADM was obtained. A linear relationship is held between the peak current and ADM concentration in the range of 1.0×10^-8-2.0×10^-6 mol·L^-1 with detection of 5.0×10^-9 mol·L^-1 by cyclic voltammetry (CV) response. The reduction process was irreversible with adsorption at the NpCo/ITO electrode. The modified electrode showed an excellent electrocatalytic activity for the ADM electrochemical reduction.