Abstract: T helper 17 cells(Th17) are a recently discovered CD4+ T cells subsets,a new member of the Th1,Th2 family.Recent studies have found that IL-17 produced by Th17 can induce bronchial epithelial cells,endothelial cells and fibroblasts secreting IL-6,IL-8,ranulocyte colony-stimulating factor and tumor necrosis factor alpha and other cytokines,and promot recruitment of neutrophils in lung.Present studies show that th17plays an important role in the bronchopulmonary dysplasia incidence mechanism,and provides a new research direction in the prevention and treatment.