Scholars often focus on the formation of vascular intimal atherosclerosis (As) plaque, but pay little attention to the immune response of vascular adventitia and its impact on the course of the disease. Previous studies have found that there are orderly aggregate of immune cells in the adventitia of aged ApoE－/－ mice, forming ectopic lymphoid tissue similar to lymph node, which is called artery tertiary lymphoid organs (ATLO), and its formation has an obvious regulatory effect on intimal As. The discovery and study of ATLO point out a new direction for the study of As and provide a good example for the study of tertiary lymphoid organ (TLO) in other diseases. Therefore, clarifying the characteristics and formation mechanism of TLO is of great significance for the prevention and treatment of As, and provides a solid foundation for its clinical application in other diseases.