Objective : The Sinseon-yukza-hwan (SSY), a Korean medicinal formula which includes Radix Rehmanniae Preparata and other medicinal herbs, has long been used for treatment of alopecia and gray hair through oral administration. This study is designed to enhance the utilization of natural materials in hair and scalp-related cosmetics. Possibility of SSY as an antioxidant was examined from its 50% ethanol extract. Methods : The antioxidative capacities were evaluated by determining total phenolic and flavonoid contents, 1,1- diphenyl-2-picryl hydrazyl (DPPH), 2`-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), reducing power and hydroxyl radical scavenging activity. Results : Total polyphenol and flavonoid contents of SSY were 25.53 ㎎ TE, tannic acid equivalent/g and 18.90 ㎎ RE, rutin equivalent/g, respectively, which correlated strongly its antioxidative activity. The DPPH and ABTS free radical scavenging activities of SSY at 0.1 ㎎/㎖ ~ 5 mg/ml were ranged from 20% to 85% and 10% to 58%, respectively. Also the hydroxyl radical scavenger activity and reducing power increased in SSY-treated group, which were significantly lower in SSY-compared to BHA-treated group. But the highest reducing power was shown as 79% from SSY-treated group, which was higher value than 65% from BHA-treatment. These results showed that SSY extract effectively inhibited the generation of free radicals in the all assay system with dose-dependent manners. Conclusions : Thus, the present study provide preclinical data to support the expanded application of SSY, which could be potential candidates for natural antioxidants.