Graphene(RGO)/MnO2/[N-butyl-3,6-carbazolevinylene-alt-(2,5-dioctyloxy)-p-phenylenevinylene]　(PPH-CAR)　ternary　nanocomposite　is　fabricated　by　a　simple　two-step　method,　which　includes　electrochemical　reduction　of　graphene　oxide　(GO)　and　oxidation　of　Mn(CH3COO)(2)　simultaneously　and　an　ultrathin　PPH-CAR　layer　coated　on　the　RGO/MnO2　surface.　The　structure　of　the　composite　is　investigated　by　X-ray　diffraction　(XRD),　X-ray　photoelectron　spectroscopy　(XPS)　and　field-emission　scanning　electron　microscopy　(FESEM).　The　results　suggest　that　the　composite　is　correctly　synthesized　and　each　component　has　good　dispersion.　Cycle　voltammetry　(CV),　charge　and　discharge　measurements　and　cycle　stability　test　are　used　to　evaluate　its　electrochemical　performance.　Because　of　the　synergistic　effect　of　each　component,　the　composite　exhibits　excellent　electrochemical　properties　with　specific　capacitance　of　175　F/g,　which　is　a　46%　increase　compared　with　RGO/MnO2.　Moreover,　it　reveals　outstanding　cycling　performance　with　more　than　90%　capacitance　retention　over　1000　cycles.　Such　ternary　composite　is　a　candidate　for　high　performance　supercapacitors　with　great　promise.