Bimodal　mesoporous　materials　were　modified　with　different　amount　of　3-aminopropyltriethoxysilane　and　employed　as　aspirin　carriers.　The　modified　and　drug　loaded　bimodal　mesoporous　materials　were　characterized　with　XRD,　FT-IR,　TEM　and　elemental　analysis　methods　to　explore　the　influence　of　amino　groups　and　drug　molecules　on　the　mesoporous　surface.　Meanwhile,　the　mesoporous　surface　energy　states　was　calculated　by　the　density　functional　theory　based　on　the　N-2　sorption　analysis.　According　to　the　surface　energy　distributions　of　samples　including　before　and　after　modification　and　drug　loading,　it　can　be　deduced　that　through　superficial　modification　with　amino　groups,　the　surface　energy　moves　to　high　state,　implying　the　introduction　of　amino　moieties　could　provide　the　mesoporous　surface　with　much　active　sites.　Besides,　the　interaction　between　the　amino　groups　and　drug　molecules　is　weak,　and　hence　the　controlled　drug　delivery　would　be　possible.　(C)　2011　Elsevier　Ltd.　All　rights　reserved.