To observe the protective effect of orally administrated Rexflavone (Sophorae fructus extract) for the postmenopausal symptoms, a randomized double-blind placebo controlled clinical trial was designed. Rexflavone significantly improved 11 menopausal symptoms including hot flash, which was evaluated by the modified Kupperman Index (KI), while hormone level and lipid profile were little changed by consumption. Rexflavone group significantly decreased KI score (-14.91 +/- 8.79) compared to placebo group (-11.45 +/- 6.62) as a representative index for improvement of menopausal symptoms (p < 0.05). We found that Rexflavone has no adverse effect to be safe for long term consumption. It was shown that the consumption of Rexflavone possessed beneficial effects on the postmenopausal symptoms in postmenopausal women.