The　development　of　high　capacitance,　high　rate　capability,　and　stability　compounded　electrochemical　energy　storage　devices　is　an　important　factor　that　is　required　to　meet　the　challenge　of　energy　depletion.　In　this　work,　a　novel　graphene-decorated　2D　Ti3C2TX/polyaniline　(GTP)　nanocomposite　was　successfully　fabricated　by　means　of　insitu　oxidation　copolymerization　of　aniline　monomers　on　the　surface　of　Ti3C2TX　nanosheets　with　the　decoration　of　small-sized　chemical-vapor-deposited　graphene　nanosheets.　The　GTP　nanocomposite　shows　promoted　pseudocapacitive　when　used　as　a　supercapacitor　electrode,　because　the　small-sized　graphene　can　effectively　prevent　aggregation　of　the　Ti3C2TX　monolayers　and　facilitate　the　uniform　growth　of　polyaniline　on　the　layered　structural　Ti3C2TX.　Furthermore,　the　small-sized　graphene　provides　more　ion/electrons　transfer　pathways,　which　acts　like　conductive　bridges　between　the　electrodes　and　the　electrolyte.　After　assembling　an　asymmetric　supercapacitor　(ASC)　device　using　GTP　as　the　positive　electrode　and　Ti3C2TX　as　the　negative　electrode,　the　device　can　operate　in　a　voltage　window　up　to　1.5V　in　1M　H2SO4.　Most　importantly,　the　GTP//Ti3C2TX　ASC　shows　an　outstanding　electrochemical　performance　compared　to　the　reported　Ti3C2TX-based　devices.