Graphene nanosheet/carbon nanotube/polyaniline (GNS/CNT/PANI) composite is synthesized via in situ polymerization. GNS/CNT/PANI composite exhibits the specific capacitance of 1035 F g(-1) (1 mV s(-1)) in 6 M of KOH, which is a little lower than GNS/PANI composite (1046 F g(-1)), but much higher than pure PANI (115 F g(-1)) and CNT/PANI composite (780 F g(-1)). Though a small amount of CNTs (1 wt.%) is added into GINS, the cycle stability of GNS/CNT/PANI composite is greatly improved due to the maintenance of highly conductive path as well as mechanical strength of the electrode during doping/dedoping processes. After 1000 cycles. the capacitance decreases only 6% of initial capacitance compared to 52% and 67% for GNS/PANI and CNT/PANI composites. (c) 2009 Elsevier B.V. All rights reserved.