A bimodal porous Cu with regular Gasar micrometer or millimeter pores and random dealloying nanometer pores was fabricated by chemical corrosion of Cu-Zn alloy layers on the inner surface of Gasar Cu pores. In order to accomplish this object, a two-step corrosion method was conducted, including the selective corrosion of Zn element from Cu-Zn alloy layers by NaOH solution, and the removal of the surface oxide obtained in the first step to expose the bottom nanoporous Cu films by HCl solution. Influences of preparation conditions, such as HCl solution concentration and processing time, NaOH solution dealloying time, Gasar pore diameter, and the distance from Gasar pore openings on the microstructure of the resulting nanoporous Cu films were discussed. (C) 2015 Elsevier B.V. All rights reserved.