Though ursodeoxycholate acid (UDCA) is the wellknown effective therapy for PBC, clinical effectiveness of UDCA may be limited by its poor absorption and extensive biotransformation. The more hydrophilic bile acid tauroursodeoxycholate (TUDCA) is the active ingredients of UDCA, and has been approved by state food and drug administration in China for treatment of cholesterol stones. So it is necessary to verify the efficacy and safety of TUDCA in the treatment of adult primary biliary cirrhosis. In this randomized, double-blinded, double-dummy, parallel-controlled and multicenter clinical trial, we detect the proportion of patients who had AKP decline more than 25% as the primary outcome; decline of AKP, total bilirubin, GGT, ALT and AST as secondary outcomes after patients were treated with TUDCA or UDCA for 24 weeks.