The research paper describes polyaniline (PANI) nanowires array on flexible polystyrene microsphere/reduced graphene (PS/rGN) film is synthesized by dilute polymerization, and then the PS microspheres are removed to form free-standing three-dimensional (3D) rGN/PANI composite film. The chemical and structural properties of the 3D rGN/PANI film are characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET), and the results confirm the 3D EGN/PANI film is synthesized successfully. When the film is used as a supercapacitor electrode, the maximum specific capacitance is as high as 740 F g(-1) (or 581 F cm(-3) for volumetric capacitance) at a current density of 0.5 A g(-1) and the specific capacitance retains 87% of the initial after constant charge discharge 1000 cycles at current density of 10 A g(-1). It is believed that the free-standing 3D rGN/PANI film will have a great potential for application in supercapacitors. (C) 2015 Elsevier B.V. All rights reserved.