Chronic inflammation plays an important role in the development of atherosclerosis (As). Immune response related mechanisms are involved in the process of arterial inflammatory disease. Regulatory T cell (T regulatory cells,Treg) is a T lymphocyte subset with unique immunomodulatory function. A great deal of evidence shows that the quantitative changes and dysfunction of Treg are closely related to the pathogenesis of As. This paper briefly describes and summarizes the mechanism of Treg in the development of As, and introduces the latest research progress of Treg as a new drug therapeutic target in the prevention and treatment of As, in order to provide new ideas for the prevention and treatment of atherosclerotic diseases.