Macrophage migration inhibitory factor (MIF) is a pleiotropic immunoregulator which has a unique structure and a chemokine-like function. Since it was dicovered in 1966, the functions of MIF have been indicated, such as non-specific immunity, the inflammatory cell recruitment, and inflammatory reaction. In addition to its eponymic activity, MIF also has a proinflammatory function and promotes the directed migration and recruitment of leukocytes into infectious and inflammatory sites; it also has functions such as anti-glucocorticoids, anti-apoptosis , and promoting the release of other cytokines. As a result, MIF plays an important role in atherosclerosis, autoimmune diseases, cancer, and metabolic diseases. In this review, we will discuss the molecular pathway, function, related diseases and clinical application of MIF.