Lymphocyte homing refers to that the lymphocytes of the blood circulation selectively pass through the post-capillary venules and directionally migrate into the peripheral immune organ or specific tissue area.The interaction between high endothelial vein after the capillaries the lymphocytes and the vascular cell adhesion molecule of tissues or organs is the molecular basis of lymphocyte homing.Lymphocyte homing is a complex process which includes a variety of adhesion molecules and affected by multiple factors regulatory.