Traditional herbal medicine is widely used among the Korean people, and other eastern Asian countries employ similar therapies as well. In recent years, due to increasing interest in herbal medicines, many researches have been made on the toxicity and side effects of herbal medications. Through private and public media, there have been many opinions suggesting taking herbal medicines is very harmful, especially on the liver and kidney functions. This assertion has been mainly presented by the doctors that practice western medicine, But this assertion is never based on adequate knowledge of herbal medicine. This study aims to provide the evidences that taking herbal medicines is safe on the renal functions. Four frequently used herbal medications(Sipjeondaebotang, Bojungigitang, Ojeoksan, and Yukmijihwangtang) were used to test the toxicity of herbal medicine oh the lab animal model(SD-Rat). There is no significant difference in body weight and kidney weight after herbal medication for 1 month. In all experimental groups, no abnormal findings were observed in histological study, and lab renal function index(BUN, creatinine, uric acid). These results say that four herbal multi-used-medicines, when medicated, is safe from the renal toxicity in lab animal model.