Abstract: Psoriasis is a common,inflammatory and proliferative disease of the skin.The creation and maintenance of psoriatic lesions require a multicellular conspiracy by which prepsoriatic skin becomes infiltrated by a variety of immunocytes triggering changes in the behavior of epidermal keratinocytes and endothelial cells.Chemokines,as a group of cytokines capable of directing cells trafficking,can be divided into 4 subclasses.They induce T cells and other cells to migrate to and reside in the skin during physiologicalresponses in inflamed or infected skin,and play important roles in the pathophysiology of psoriasis.