We report the synthesis of mesoporous alumina (MA)-supported sodium tripolyphosphate (STPP)/chitosan (Ch) composite (denoted as MA@STPP/Ch) by a layer-by-layer self-assembly method. The multilayered MA@STPP/ Ch is nontoxic and shows excellent CO2 adsorption capacity (maximum: 278.96 mg g(-1) at 50 degrees C) and reusability, better than that of MA (97.24 mg g(-1) at 50 degrees C). The enhanced CO2 adsorption could be ascribed to the synergism between porous structure and functional groups of Ch.