Objective: To analyze the percentage of FOXP3+ regulatory T cells in peripheral blood from patients with diabetes of different types. Methods: Three groups were included:type 1 diabetes(n = 43 cases),type 2 diabetes(n = 16 cases) and healthy control (n = 19 cases). Zinc transporter 8 antibody (ZnT8A),glutamic acid decarboxylase antibody (GADA) and islet cell antibody (ICA) were detected by radioligand binding assay. The proportions of regulatory T cells,CD4+CD25+FOXP3+T cells and CD4+CD25+T cells,in peripheral blood were determined by flow cytometry. Results: ① In the peripheral blood,the percentages of CD4+CD25+T cells in CD4+T lymphocytes from patients with type 1 diabetes or type 2 diabetes were lower than those of healthy control;② In the peripheral blood,patients with type 1 diabetes showed lower ratio of CD4+ CD25+ FOXP3+ T cells compared with healthy control and patients with type 2 diabetes;③ There was no significant correlation between the duration of diabetes and the percentage of peripheral CD4+CD25+FOXP3+ regulatory T cells or CD4+CD25+T cells. Conclusion: In the peripheral blood,the FOXP3+ regulatory T cells population was deficiency in patients with type 1 diabetes. Type 2 diabetes had small influence in the percentage of FOXP3+ regulatory T cells. There was no significant relationship between the percentage of FOXP3+ regulatory T cells and duration of type 1 diabetes.