Objective Type 1 diabetes is caused by peripheral immune regulation disorder and with the dysfunction of regulatory T cells（Treg) and cytokine activities to trigger effector T cells (Teff) abnormal activation with high expression of relevant cytokines to mediate the destruction of islet β-cells. In this study, the plasma concentrations of some cytokines expressed by relevant Th1, Th2, Th17, Treg cells were analyzed in type 1 diabetes (T1DM) and type 2 diabetes (T2DM) patients and the controls to explore. Methods The peripheral blood samples from 63T1DM, 60 T2DM and 40 normal controls were collected, sandwich enzyme-linked immunosorbent assay was used for assessment of the serum levels of IFN-γ, IL-4, IL-10 and IL-17. Results The average serum level of IFN-γ was higher in T1DM and lower in T2DM than in the control (400.95±51.44 , 303.67±50.33 and 340.99±39.47pg/ml, respectively; triplets P<0.01). The level of IL-4 was lower in T1DM than in both T2DM and the control (21.63±4.22 , 32.69 ± 4.10 and 31.49±2.42pg/ml, respectively; both p<0.01), however, slightly higher in T2DM compared to the control(p<0.05). The level of IL-10 was lower in T1DM than in both T2DM and the control, slightly and significantly lower in T2DM than in control (15.69± 3.22, 22.49±2.95 and 24.13±2.17 pg/ml, respectively; triplets P<0.01). The level of IL-17 in T1DM was significantly higher in T1DM than in T2DM and the control, and slightly higher in T2DM compared to control (26.87±2.47, 21.50±2.15, 19.41±2.80 pg/ml, respectively; triplets p<0.01). Conclusions A significantlydysfunction of the subsets of Th1/Th2 and Th17/Treg in T1DM was found. And CD4+T lymphocyte subsets may be involved in the development of both T1DM and T2DM, but may in a different way and with different mechanisms. These provide us a new way thinking of the treatment and prevention of T1DM and T2DM. 【Key words】: Type 1 diabetes mellitus.