Different mass ratios of polypyrrole (PPy) to graphene hydrogel (GH) nanocomposites were synthesized by hydrothermal reduction of graphene oxide and chemically oxidative polymerization of pyrrole, forming a three-dimensional framework of PPy wrapped on the surface of GH without adding any toxic reductive agents. Electrochemical tests show that PPy/GH(15) nanocomposite exhibits unique electrochemcial properties, such as enhanced electrolytic permeability and high electric capacity. Thanks to the synergistic effect of the pseudo-capacitance of PPy and the electric double layer capacitance of GH, PPy/GH(15) exhibits a high specific capacitance of 375 F g(-1) at a scan rate of 10 mV s(-1). In addition, the PPy/GH(15) electrode shows good cycling stability, and its specific capacitance retention is 87% even after 4000 charge-discharge cycles in the potential window of -0.1 to 0.6V, suggesting it an ideal electrode material for supercapacitor. (C) 2013 Elsevier Ltd. All rights reserved.