In order to overcome the unsatisfactory stability of polyaniline (PANi) modified graphite felt (GF) electrode, graphene oxide (GO) was introduced into PANi/GO composite for GF modification in this study. PANi/GO composite was fabricated via a convenient and low-cost electropolymerization method. Scanning electron microscope, Raman spectrum and Fourier transform infrared spectrum demonstrated that PANi/GO composite was successfully coated onto the GF surface. The electrochemical activity, pH dependence and stability of the PANi/GO modified GF electrode were significantly improved after modification, as was indicated by cyclic voltammetry and chronoamperometric tests. The application of PANi/GO modified GF electrode in a bioelectrochemical system (BES) confirmed its superior electrogenesis performance, in terms of much higher maximum power density achieved. The improved biocompatibility, electrochemical activity and stability suggested that PANi/GO modified GF electrode had a promising potential in the BES application for the wastewater treatment. (C) 2015 Elsevier B.V. All rights reserved.