Inchin-ko-to (ICKT) prevents Fas-mediated liver injury. This study evaluates the effect of ICKT on conventional markers of liver function (LF) and liver fibrosis in is postoperative biliary atresia (BA) patients aged 3 to 23 years with elevated glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), gamma -glutamyl transpeptidase (gamma GTP) but normal serum total bilirubin (T-Bil) levels. ICKT (0.15 g/kg per day) tvas administered orally for 1 year. Serum GOT, GPT, gamma GTP, total bile acids (TBA), and T-Bil as markers of LF and hyaluronic acid (HA), prolyl hydroxylase (PH), procollagen. III peptide (PIIIP), and type TV collagen as markers of liver fibrosis were measured before and after treatment in each patient and compared statistically. All patients tolerated ICKT well, and there were no side effects. The percentage of subjects who improved after ICKT was 45% for serum GOT, 72% for GPT, 72% for gamma GTP, 72% for TEA, 67% for HA, 40% for PH, 50% for PIIIP,, and 23% for type IV collagen. Changes in the mean values of all serum markers were statistically significant (P < 0.01). It is concluded that long-term administration of ICKT in postoperative BA patients improves liver status as assessed by markers of LF and fibrosis.