Zinc oxide thin films have been grown by electrodeposition technique onto Cu and ITO-coated glass substrates from an aqueous zinc nitrate solution with addition of sodium thiosulfate at 90 ℃.The effects of sodium thiosulfate on the electrochemical deposition of ZnO were investigated by cyclic voltammetry and chronoamperometry techniques.Deposited films were obtained at-0.60 V vs.SCE and characterized by XRD,SEM,FTIR,optical,photoelectrochemical and electrical measurements.Thickness of the deposited film was measured to be 357 nm.X-ray diffraction results indicated that the synthesized ZnO has a pure hexagonal wurtzite structure with a marked preferential orientation along (002) plane.FTIR results confirmed the presence of ZnO films at peak 558 cm-1.SEM images showed uniform,compact morphology without any cracks and films composed of large flower-like ZnO agglomerates with star-shape.Optical properties of ZnO reveal a high optical transmission (＞80％) and high absorption coefficient (α ＞ 105 cm-1) in visible region.The optical energy band gap was found to be 3.28 eV.Photoelectrochemical measurements indicated that the ZnO films had n-type semiconductor conduction.Electrical properties of ZnO films showed a low electrical resistivity of 6.54 Ω·cm,carrier concentration of-1.3 × 1017 cm-3 and mobility of 7.35 cm2V-1s-1.