To detect the correlation between Interleukin-10 and CD4+CD25+Foxp3+regulation T cells ( Treg) and to explore the significance and mechanism of them in leprosy patients.Methods:We used the cytometric bead arra (CBA) to detect the serum Interleukin-10 in 30 leprosy patients and we used flow cytometry to test the Treg cells in 51 leprosy persons.Results:The con-centration of serum IL-10 in leprosy patients(130.00±54.27)pg/ml was higher than normal people(15.64±7.11)pg/ml,(P<0.05);The percentage of Treg cells in leprosy patients(17.626±8.1977)%was higher than normal people(9.998±1.7062)%,(P<0.05).The relevance between IL-10 and Treg is positive and linear ,( P<0.05 ).Conclusion: The imbalance between IL-10 and Treg cells may lead to immune abnormal in leprosy patients.