Abstract: To investigated the changes in CD4+CD25+ CD127low regulatory T cells (Tregs) in the peripheral blood of patients with hepatocellular carcinoma ( HCC ) and the clinical significance of these changes. Methods: Peripheral blood mononuclear cells from 40 patients with HBV-induced HCC (7 patients with stage A, 8 with stage B, 20 with stage C, and 5 with stage D, based on Barcelona Clinic Liver Cancer Staging Classification), 35 patients with chronic HBV infection, and 28 healthy controls were isolated and labeled with monoclonal antibodies to CD4, CD25, and CD127. Surface expression profiles were then determined by flow cytometry ( FCM ). Results: The percentage of CD4+CD25+ CD127low regulatory Tregs was higher in the CD4+T cell fraction from HCC patients than in the CD4+T cell fraction from both CHB patients ( P = 0.017 ) and healthy subjects ( P = 0.000 ). The percentage of CD4+CD25+ CD127low Tregs was higher in the CD4+T cell fraction from CHB patients than in that from healthy subjects ( P = 0.035 ). In addition, the percentage of CD4+CD25+ CD127low Tregs was higher in the CD4+T cell fraction from stage-C HCC patients than in that from stage-A HCC patients ( P = 0.020 ) and stage-B HCC patients ( P = 0.019 ). Conclusion: There was an abnormal elevation of circulating CD4+CD25+ CD127low Tregs, which may be an important mechanism for HCC immune evasion. This elevation was associated with the clinical stage and progression of HCC.