An　SnO2-decorated　graphene/polyaniline　(GSP)　nanocomposite　with　homogeneous　structure　was　prepared　and　adopted　to　achieve　high　electrochemical　performance　for　supercapacitor　electrode.　Graphene　sheets　were　decorated　with　tin　dioxide　(SnO2)　particles,　which　effectively　hinder　the　restacking　of　graphene　nanosheets,　and　then　were　used　as　substrates　for　an　in-situ　polymerization　of　aniline　monomers.　The　GSP　nanocomposite　was　characterized　by　field　emission　scanning　electron　microscopy,　X-ray　diffraction,　Fourier　transform　infrared,　UV-Visible　and　X-ray　photoelectron　spectroscopy.　The　results　revealed　that　polyaniline　nanorods　were　orderly　and　vertically　aligned　on　the　SnO2-decorated　graphene　nanosheets　via　π-π　stacking　effect　between　basal　planes　of　graphene　nanosheets　and　phenyl　group　of　polyaniline.　The　GSP　nanocomposite　exhibited　an　excellent　specific　capacitance　of　429　F　g-1　at　a　current　density　of　1　A　g-1,　excellent　cycling　stability　and　rate　capability,　which　suggested　a　promising　application　for　supercapacitor.　©　2015　.