Abstract: Immunotherapy for pancreatic cancer is not effective in clinical trials, mainly because of its tumor microenvironment (TME) with high immunosuppression. Regulatory T cells (Tregs) are a subset of T cells that control the autoimmune response and are one of the main components of immunosuppressive TME. It was found that Tregs could regulate the immune response, inhibit the function and activity of effector T cells, thus inducing immune tolerance and maintaining immune homeostasis. In the TME of pancreatic cancer, Tregs could inhibit the immune response and induce the immune escape of tumor cells, which affect the prognosis and therapeutic effect of patients. This review summarizes the mechanism of Tregs in the immune microenvironment of pancreatic cancer and its clinical significance in order to provide new insights for the immunotherapy of pancreatic cancer.