Objective To investigate the immunological improvement effects of different doses of ursodeoxycholic acid( UDCA) on patients with different stages of primary biliary cirrhosis( PBC) and enhance the understanding of the roles of the immune system in the disease,and to provide evidence for the standardized clinical treatment of PBC. Methods One hundred and eighty patients with PBC who were admitted to our hospital from March 2012 to Janurary 2014 were enrolled and equally divided into three classes according to the stage of PBC: early stage,cirrhotic stage,and poor biochemical response stage. Patients in each class were equally divided into three groups according to the dose of UDCA: 8-10,13-15,and 20-25 mg·kg-1·d-1. The general information,clinical symptoms,biochemical indices,and changes in T lymphocyte subsets and cytokines in peripheral blood after the treatment with different doses of UDCA were analyzed. Comparison of continuous data was performed by t test,and comparison of categorical data was performed by χ2test. Results In patients with early-stage PBC who were treated with 13-15 mg·kg-1·d-1UDCA,the percentage of CD3+CD4+T cells,CD4+/ CD8+ratio,and expression of interferon-gamma were significantly reduced after treatment( 54. 8% ± 11. 6% vs 34. 7% ± 7. 7 %,t = 6. 5,P < 0. 05; 2. 3 ± 1. 0 vs 1. 6 ± 0. 6,t = 2. 7,P < 0.05; 33. 0 ± 12. 3 vs 23. 7 ± 7. 2 ng / L,t = 2. 9,P < 0. 05),while the secretion of interleukin-4 was significantly increased after treatment( 29.0 ± 4. 6 vs 38. 5 ± 7. 1 ng / L,t = 5. 0,P < 0. 05). Conclusion The UDCA with a dose of 13-15 mg·kg-1·d-1can substantially improve the immune status in patients with early-stage PBC. The application of UDCA should be standardized in order to achieve the desired response.