The aim of the present study is to determine clinical efficacy and adverse reaction of yugan-tang. We compared symptoms and liver function test results of 160 patients with damp-heat type liver disease in before and after taking yugan-tang. The patients took 200ml yugan-tang two times daily for three months. Then we analyzed these datas statistically. The overall therapeutic effect was "markedly improved" in 70 of 160 patients (43.75%) and "improved" in 75 of 160 patients (46.88%). yugan-tang markedly improved damp-heat type liver disease, especially jaundice, abdominal distention, hypochondriac pain, nause, vomiting and anorexia. Alanine aminotransferase (ALT) level and total bilirubin (TBIL) level were within normal limits at baseline. But albumin-globulin ratio (A/G) level was not changed markedly. I think that yugan-tang is worth applying widely to clinic.