OBJECTIVE: To observe the efficacy of ursodeoxycholic acid (UDCA) combined with Tongdan: Decoction () on immunological indices and histopathological changes in patients with primary biliary cirrhosis (PBC) of IIor III histological stage. METHODS: Sixty PBC patients were assigned randomly and equally: to the control group treated with UDCA alone and the treatment group treated with UDCA combined with Tongdan Decoction. The immunological indices and histopathological changes were detected before and after 24-week treatment, and the follow-up lasted for 1-3 years. RESULTS: After 24-week treatment, CD4(+)CD28(-) in the peripheral blood was lowered and CD4(+)CD25(+) was increased in both groups, and better effect was shown in the treatment group (P<0.01). The levels of IgM, IgG, and IgA decreased markedly after 96-week treatment in the treatment group (P< 0.05, P< 0.01), while in the control group, only the latter two showed significant decrease after 148 week (all P<0.05). At the end of the 3-year follow-up, the medians of histopathological