Graphene nanosheet/carbon nanotube/polyaniline (GNS/CNT/PANI) composite is synthesized via in situ polymerization. GNS/CNT/PANI composite exhibits the specific capacitance of 1035Fg−1 (1mVs−1) in 6M of KOH, which is a little lower than GNS/PANI composite (1046Fg−1), but much higher than pure PANI (115Fg−1) and CNT/PANI composite (780Fg−1). Though a small amount of CNTs (1wt.%) is added into GNS, 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.