The polyaniline/activated mesocarbon microbeads (PANI/ACMB) composites are prepared by in situ chemical oxidation polymerization. Fourier infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM) have been utilized to characterize the structure and morphology of PANI/ACMB composites. It has been found that PANI is uniformly deposited on the surface of the ACMB to form the leechee-like morphology. The supercapacitive behaviors of the PANI/ACMB composites are investigated with cyclic voltammetry (CV), galvanostatic charge/discharge and cycle life measurements. The results obtained from cyclic voltammograms show that the composites have a maximum specific capacitance of 433.75 F g(-1). Moreover, the electrochemical performance of the coin supercapacitor used PANI/ACMB composites as electrode active material represents both high specific capacitance and excellent cycle stability, indicating that the PANI/ACMB composites will be a kind of potential electrode active materials with excellent specific capacitance and enhanced cycle life for application in high performance supercapacitors. Copyright (c) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.