Existing literature on the hemolytic methods for potency determination of saponinbearing drugs was examined. In the activity determination of Japanese senega, hemolytic index was obtained by using rabbit blood in a phosphate buffer solution of pH 7.4, Merck's pure Saponin as the standard. As a result, it was found that the domestic product possessed a potency equal to the drug of S. B. Penick & Co., which is assumed to be the Northern senega (cf. Table I)