The WO3/PANI core/shell nanowire array is prepared by the combination of solvothermal and electropolymerization methods. The core/shell nanowire array film shows remarkable enhancement of the electrochromic properties. In particular, a significant optical modulation (59% at 700 nm), fast switching speed, high coloration efficiency (86.3 cm(2) C-1 at 700 nm) and excellent cycling stability are achieved for the core/shell nanowire array film. The improved electrochromic properties are mainly attributed to the formation of the donor-acceptor system, and the porous space among the nanowires, which can make fast ion diffusion and provide larger surface area for charge-transfer reactions. The data indicate great promise for the WO3/PANI core/shell nanowire array as a potential multicolor electrochromic material. (C) 2013 Elsevier B.V. All rights reserved.