Objectives : To establish objective and scientific evidence of Korean medicine (KM), the papers on Oryeong-san (Wuling-san) frequently used in medical institutions of Korean Medicine were analyzed. Methods : The papers were classified by the registration of domestic or international journals, the year of publication, experimental fields and the kinds of studies on biological activities. The therapeutic mechanism was investigated in accordance with therapeutic effect of Oryeong-san (Wuling-san). Results : Out of 57 articles selected, 16 were published in domestic journals, 17 were in Chinese journals and 24 were in Japanese journals. Most papers reported as biological activities were on improvement of renal function. Oryeong-san (Wuling-san) increased urine factor such as urine excretion and electrolyte balance while decreasing proteinuria, serum factors including creatinine, cholesterol and triglyceride. In addition, injured renal tissue was recovered normally and gene expression controlling urine excretion was down-regulated. Conclusions : Improvement of renal function could be interpreted as objective and scientific evidence for Oryeong-san (Wuling-san).