Itch results from complex interaction among multiple factors.The exact mechanism of itch is still unknown.It has been evidenced that itch is related to specific neural pathways.A variety of endogenous mediators have proved to be associated with the pathogenesis of pruritus.Recent studies have demonstrated that the expression of histamine 4 receptor,protease-activated receptor-2,interleukin-31 receptor and neurokinin-1 receptor in afferent nerve fibers of skin may mediate the occurrence of itch.Neurotrophins,nerve growth factors and their receptors may serve as a sensitizer to promote the occurrence and development of pruritus.These mediators and their receptors are not independent,but closely contact with nerve cells,immune cells and skin cells,in the pathophysiological mechanism of itch. Key words: Pruritus; Receptor; Immunity