Abstract: The porous starch with immobilized catalase was prepared and dispersed in the spinning dope to be spinned into functional cellulose acetate tow. The physical properties, surface morphology of the functional cellulose acetate tow and the routine analytes and free radicals in mainstream smoke of cigarette tipped with the filter make of the tow were analyzed. The results showed that: the running property of the functional cellulose acetate tow was similar to that of normal tow. The tar delivery of mainstream cigarette smoke reduced by 10%, and the deliveries of nicotine and CO were almost unchanged. The contents of particulate phase and gas phase free radicals in smoke decreased by 38.36% and 28.57%, respectively.