The　pH-sensitive　poly(D-A)　grafted　amine-functionalized　bimodal　mesoporous　silica　(D-A/BMMs)　was　prepared　by　a　facile　method　used　as　a　drug　delivery　vehicle.　They　exhibited　superior　properties　such　as　good　dispersion　in　aqueous　medium,　high　drug　loading　efficiency,　improved　stability　and　high　drug　release　rates.　Meanwhile,　its　structural　features　and　performances　in　a　controlled　delivery　of　ibuprofen　(IBU)　were　systematically　investigated　by　using　XRD,　N-2　adsorption　and　desorption,　SEM,　TEM,　FT-IR,　elemental　analysis　and　TG　techniques.　The　results　demonstrated　that　the　obtained　nanocomposite　presented　a　flexible　control　over　drug　release　by　controlling　the　grafting　amount　of　D-A　onto　the　mesopores　surface　of　aminated　BMMs.　The　cumulative　percent　release　of　IBU　from　D-A/BMMs　was　found　to　be　much　higher　at　pH　7.4　than　at　pH　2.0.　The　release　rate　was　very　slow　in　an　acidic　medium　but　became　faster　in　a　neutral　medium,　owing　to　hydrogen　bonding　in　an　acidic　medium　and　electrostatic　repulsion　between　negatively　charged　carboxyl　groups　in　an　alkaline　medium.