Preparation　of　mono-vinyl　substituted　cyclodextrin　(CD)　monomers　is　particularly　challenging　due　to　the　presence　of　numerous　equally　reactive　hydroxyl　groups　on　CD,　which　limits　the　synthesis　of　CD-pendant　polymers　with　well-defined　structure,　high　CD　density　and　flexible　functionality.　In　this　work,　a　new　mono-methacrylate　substituted　cyclodextrin　(MCD)　was　successfully　prepared　under　mild　reaction　conditions.　Thus,　well-defined　hydrophilic　diblock　copolymer　poly(ethylene　glycol)-b-poly(cyclodextrin)　(PEG-b-PCD)　can　be　easily　synthesized　via　atom　transfer　radical　polymerization　of　MCD　from　poly(ethylene　glycol)　macroinitiator.　The　block　copolymer　was　able　to　include　a　variety　of　guest　molecules　and　self-assembled　into　advanced　nanostructures　due　to　the　synergistic　effect　of　CD　moieties.　By　altering　the　type　of　guest　molecules　and　the　ratio　of　PEG-b-PCD　to　guests,　the　self-assembled　nanostructures　showed　different　size　and　morphology.　The　strategy　developed　in　this　study　provides　a　facile　and　general　method　for　the　design　of　nanostructures　based　on　well-defined　CD-pendant　polymers,　and　these　nanostructures　may　find　applications　in　the　fields　of　drug　and　gene　delivery,　self-healing　materials,　catalysts　and　coatings.