A facile approach has been developed to fabricate mesoporous PANI film on ultra-thin graphene nanosheet (G-mPANI) hybrid by in situ polymerization using graphene-mesoporous silica composite as template. Due to its mesoporous structure, over-all conductive network, G-mPANI electrode displays a specific capacitance of 749 F g−1 at 0.5 A g−1 with excellent rate capability (remains 73% even at 5.0 A g−1), much higher than that of pristine PANI electrode (315 F g−1 at 0.5 A g−1, 39% retention at 5.0 A g−1) in 1 mol L−1 H2SO4 aqueous solution. More interestingly, the G-mPANI hybrid can maintain 88% of its initial capacitance compared to 45% for pristine PANI after 1000 cycles, suggesting a superior electrochemical cyclic stability.