We report a facile and effective method for synthesizing polypyrrole/modified graphite oxide (PPy/MGO) composites by in situ polymerization. The graphite oxide (GO) is modified with hexadecylpyridinium chloride (CPC) and then composited with PPy. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) results demonstrate that PPy chains may combine with CPC molecule via pi-pi stacking interaction and the structures of PPy/GO and PPy/MGO composites are completely different. Cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectrum (EIS) tests indicate that, at the current density of 1 A g(-1), the specific capacitance and energy density of PPy/MGO are 202 F g(-1) and 8.49 Wh kg(-1) in three-electrode systems and those are 87 F g(-1) and 10 Wh kg(-1) in two-electrode systems; the capacitance retention of PPy/MGO is 83.8% after 1000 cycles at a scan rate of 1 A g(-1); PPy/MGO also exhibited excellent energy performance from Ragone charts. Based on these properties, the PPy/MGO composites may become a promising material for supercapacitor applications. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.