Abstract: Three composite materials of chitisan with different kinds of molecular sieves were prepared and their micromorphology and physical properties were studied by scanning electron microscope and ASAP 2000 automatic adsorber. The 3 composite materials and the chitosan as well as the 3 kinds of molecular sieves were added separately into the filter tips of 13 cigarettes and their adsorptive efficiency toward the low molecular aldehydes,ketones and some other harmful substances (e.g. tarnicotine,carbon monoxide etc.) were tested. As shown by the analytical results found by HPLC,best absorptive efficiency toward the 8 carbonyl compounds were obtained with those filter tips filled with composite materials,especially with the material D and E,while no significant mass changes were observed with the compounds of tar and nicotine. However,the composite materials showed a definite adsorption toward carbon monoxide,thus improving taste and decreasing irritation of the tobacco in smoking.