Cuprous oxide (Cu2O) thin films were formed on indium-doped tin oxide (ITO) covered glass substrates by cathodic deposition of cupric acetate. The influence of additives on crystal morphology of Cu2O was studied in acetate bath. We found that the simple salts contained Cl-ions in electrolyte could change the crystal morphology. It was shown that the morphology evolved from star like to cube like by increasing the concentration of Cl- ions of the capping agents, which indicated that Cu2O crystal morphology varied with the Cl- ions concentration. (C) 2007 Elsevier B.V. All rights reserved.