Objective:To observe changes of the number and function of peripheral blood Vδ1 T cells in patients with sepsis, and preliminary study on the role of Vδ1 T cells in the pathogenesis of sepsis. Methods: A total of 40 patients with sepsis who underwent ICU treatment and 40 healthy controls (HC)who underwent physical examination in authors’ affiliated hospital from December, 2012 to December, 2014 were enrolled in this study. Peripheral venous blood samples (10 mL) were taken from both groups. The proportion of Vδ1 T cells and Foxp3 expression on Vδ1 T cells were detected by flow cytometry (FCM). The inhibition effect of Vδ1 T cells on CD4+ T cell proliferation was detected by CFSE staining. After coculture for 72 h, the inhibition effects of Vδ1 T cells on the IFN-γand TNF-α production ability of CD4+ T cell were detected by FCM. Results: The proportion of Vδ1 T cells in HC was(1.04 ± 0.22)%, and in sepsis was (3.35 ± 0.55)%, the proportion of Vδ1 T cells between HC and sepsis had statistical significance (P < 0.01). The proportion of Foxp3 expression on Vδ1 T was (10.02 ± 2.31) % in HC, and was (16.83 ± 3.63)% in sepsis, the proportion of Foxp3 expression on Vδ1 T between HC and sepsis had a statistical significance (P < 0.01). The inhibitory effect of Vδ1 T cells from HC on the proliferation, IFN-γ and TNF-α production ability of CD4 T cell were (44.26 ± 6.31)%,(34.84 ± 4.83)% and (39.31 ± 4.91)%, respectively; and the inhibitory effect of Vδ1 T cells from sepsis on the proliferation, IFN-γand TNF-α production ability of CD4 T cell were (62.35 ± 5.91)%,(50.37 ± 4.77)% and(54.94 ± 5.71)%, respectively. The inhibitory effect of Vδ1 T cells between HC and sepsis had a statistical significance (P < 0.01). Conclusion: Vδ1 T cells from sepsis have strong inhibitory function, resulting in immune function inhibition, finally resulting in sepsis.