Abstract: Th17 cells are a newly appreciated T-helper cell subset, which distinct from both Th1 and Th2 cells. The cytokines produced by Th17 cells include IL-17A，IL-17F，IL-21，IL-22，IL-6，TNF-α and so on. These cytokines can play an important role in the onset and development of dermatosis. Investigations about the relationship between Th17 cells related cytokines and dermatosis may illustrated more about the nosogenesis of dermatosis such as psoriasis and atopic dermatitis，and provide new target for their therapy.