The effect of adventitia on the occurrence and development of atherosclerosis (As) is getting more attentions. Fibroblasts, mast cells, dendritic cells, vasa vasorums, vascular-associated lymphoid tissues, and vascular peripheral nerves are related to the occurrence and development of As. This essay summarizes studies on the changes in adventitia in As process and its effect on the occurrence and development of As, as well as the latest progress.