A　new　nanocomposite,　poly(aniline-co-diphenylamine-　4-sulfonic　acid)/graphene　(PANISP/rGO),　was　prepared　by　means　of　an　in　situ　oxidation　copolymerization　of　aniline　(ANI)　with　diphenylamine-4-sulfonic　acid　(SP)　in　the　presence　of　graphene　oxide,　followed　by　the　chemical　reduction　of　graphene　oxide　using　hydrazine　hydrate　as　a　reductant.　The　morphology　and　structure　of　PANISP/rGO　were　characterized　by　field-emission　(FE)　SEM,　TEM,　X-ray　photoelectron　spectroscopy　(XPS),　Raman,　FTIR,　and　UV/Vis　spectra.　The　electrochemical　performance　was　evaluated　by　cyclic　voltammetry,　galvanostatic　charge-discharge,　and　electrochemical　impe-dance　spectroscopy.　The　PANISP/rGO　nanocomposite　showed　a　nanosized　structure,　with　sulfonic　polyaniline　nanoarrays　coated　homogeneously　on　the　surface　of　graphene　nanosheets.　This　special　structure　of　the　nanocomposite　also　facilitates　the　enhancement　of　the　electrochemical　performance　of　the　electrodes.　The　PANISP/rGO　nanocomposite　exhibits　a　specific　supercapacitance　up　to　1170　Fg(-1)　at　the　current　density　of　0.5　Ag-1.　The　as-prepared　electrodes　show　excellent　supercapacitive　performance　because　of　the　synergistic　effects　between　graphene　and　the　sulfonic　polyaniline　copolymer　chains.