We　presented　a　facile　method　to　prepare　graphene　quantum　dots　(GQDs)　from　double-walled　carbon　nanotube　with　blue　light　emission　in　a　chlorobenzene　solution,　which　enabled　the　preparation　of　GQD-polymer　hybrid　nanocomposite.　The　wavelength-dependent　fluorescent　lifetime　of　the　GQDs　was　investigated　by　using　time-resolved　photoluminescence　technique.　Significantly,　nonvolatile　rewritable　memory　effect　was　observed　for　the　GQD-based　nanocomposite,　suggesting　the　promising　applications　of　GQDs　in　data　storage.　Moreover,　due　to　the　easy　solution　process,　we　demonstrated　the　design　and　realization　of　flexible　GQD-based　memory　device.　This　work　may　expand　the　application　of　GQDs　to　the　portable　electronic　devices.　(C)　2013　Elsevier　B.　V.　All　rights　reserved.