Large scale of ZnO nanosheets and sunflower structures were fabricated by anodization of zinc in (NH4)(2)SO4 and NH4Cl aqueous electrolytes. The products were characterized via scanning electron microscope, transmission electron microscope and X-ray diffraction analysis. Results show that the sheets are about 20-50 mu m in dimension and 20 nm in thickness. The sunflower microstructures are about 400-500 mu m in dimension. The possible growth mechanism is suggested on the basis of experimental results. (C) 2011 Elsevier B.V. All rights reserved.