Abstract: Zinc oxide(ZnO) films were electrodeposited from low concentration of Zn(NO3)2 as electrolyte on the ITO substrates. The electrochemical method has the ability to “tailor” deposited structure, properties and to form a highaspectratio ZnO film. And optimized condition hexagonal crystal of ZnO film has been determined ultimately. The morphology, microstructure and optical performance of ZnO films were characterized by scanning electron microscopy (SEM)， transmission electron microscopy (TEM) , Xray diffraction (XRD) etc. The effects on different concentrations of Zn2+， NO3- and C- in electrolyte on the growth of ZnO nanopillars were studied. The results showed that ZnO nanocrystalline thin films has wrutzite structure and growth tendency of ［002］ orientation obviously. Optical characterizations showed that the maximum value of optical transmittance of the film up to 75%, the optical bandgap energy value was about to 3.28 eV.