Saengmaeksan (SMS) is a well known Korean traditional herbal prescription, which consists of 3different herbs, Radix Ophiopogonis, Radix Ginseng, and Fructus Schisandrae. SMS has beencommonly used in various disease including respiratory system and cardiovascular System inKorea. The objective of this study is to find out the improving effects of SMS against DextranSulfate Sodium (DSS)-induced ulcerative colitis. SMS reduced clinical signs of DSS-inducedcolitis, including body weight loss, shorten colon length, and increased disease activity index. Theresults showed that SMS significantly inhibited the activation of nuclear factor-kB p65 in thecolon tissues of DSS-treated mice. In addition, we observed that result showed that the levels ofIL-6 in plasma were increased in DSS treated group compared to those of the normal group, butthese increased levels were reduced by administration with SMS. Taken together, these findingssuggest that SMS has improving effects on DSS-induced ulcerative colitis, which may explain itsbeneficial effect in the regulation of chronic intestinal inflammation.