Dextran-poly(acrylic　acid)　copolymers　(D-A)　are　prepared　through　copolymerizing　of　acrylic　acid　(AA)　with　dextran.　Their　structural　properties　and　performances　are　characterized　using　various　methods.　The　results　indicate　that　the　carboxyl　groups　of　poly(acrylic　acid)　strongly　interact　with　the　proton　acceptors　of　glucose　units　in　dextran,　and　the　effects　of　AA/dextran　molar　ratio　on　the　pH　sensitivity　of　obtained　copolymers　are　remarkable.　The　D-A　copolymer　shows　a　smart　pH　response,　specifically,　shrinkage　in　a　low　pH　medium　and　swelling　at　high　pH.　The　potential　application　of　D-A　copolymer　as　a　drug　delivery　matrix　is　explored　using　ibuprofen　as　a　model　drug.