Abstract: The T-helper typer 17 cells/interleukin 17 (Th17/IL-17) axis,which plays an important role in the pathogenesis of autoimmune diseases,is also implicated in the development of many immune-mediatedskin diseases.Immunosuppressants and immunoregulators have been extensively used in the treatment of autoimmune and inflammatory skin diseases.The exact action mechanisms of these drugs are complicated,andrecent studies have demonstrated that they may exert immunoregulatory roles by inhibiting the Th17/IL-17 axis.Many drugs commonly used in dermatology,such as cyclosporine A,triptolide,tretinoin,vitamin D,tacrolimusand mycophenolic acid,have shown an inhibitory effect on the Th17/IL-17 pathway.To explore new action mechanisms of these immunoregulatory drugs may provide theoretical basis for their wider application in the treatment of Th17-mediated autoimmune diseases,and offer clues to further researches for therapeutic targetsin the Th17/IL-17 axis.