This study describes the manufacturing method of antioxidant filter and evaluate the reduction of free radical and biological activity from mainstream smoke. When we used spray-brush for the application of antioxidant solution to the filter, cv(coefficient of variation) levels of antioxidant added to filter ranged within 3 %, which means stable and constant feeding process. 0.3~0.5mg per cigarette of antioxidant were sprayed to acetate and active carbon part in the filter plug, respectively. It was considered that the use of antioxidant added filter resulted in the reduction of the gaseous compounds of free radicals from 17 % to 19 % in the mainstream smoke. Variation for removal efficiency of free radical in antioxidant filter added to acetate part was more pronounced than that of filter added to active carbon part. Smoking deliveries of tar, nicotine for the antioxidant added filters were similar when comparing to the non-antioxidant added filter, but the delivering amounts of isoprene were significantly reduced. The estimation of consumed GSH(glutathion) showed that the gaseous toxicity of the antioxidant added filter was 14 % ~ 23 % lower than that of non-antioxidant added filter. No significant differences were observed for the total taste quality in sensory evaluation.