Incompletely reduced graphene (RG) was prepared by reduction of graphite oxides via microwave irradiation at the power of 800 W and 1200 W, respectively. Fourier transform infrared spectra and X-ray photoelectron spectroscopy analyses showed that the RG contains flourish oxygen functional groups such as carboxyl, phenol, carbonyl, and quinone groups. X-ray diffraction, scanning electron microscopy and transmission electron microscopy were employed to investigate the structure, morphology of the RG samples. The electrochemical performance of the RG electrodes were measured in 5 M NaOH, 1 M H2SO4 and 1 M Na2SO4 electrolytes respectively. The supercapacitor performance of oxygen containing functional group behavior was investigated. The specific pseudocapacitance per unit atomic percentage for either carboxyl or phenol group in 1 M H2SO4 and either carbonyl and quinone group in 5 M NaOH were obtained by galvano-statically charge/discharge measurements (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.