Abstract: Sphingosine 1-phosphate(S1P)is a pleiotropic sphingolipid metabolite that has been shown to regulate important physiological function by activation of its G-protein-coupled receptors S1PRs. S1P has been identified as an important signaling molecule in maintaining epithelial and endothelial barrier function. S1P signaling pathway is involved in epithelial and endothelial barrier function by regulation of adherens junction and tight junction assembly, cytoskeletal reorganization, and focal adhesion formation. Thus, S1P signaling pathway may become a novel therapeutic target for cell barrier dysfunction during some illnesses such as acute lung injury, inflammatory bowel disease and sepsis. In this review, the research progress of S1P signaling pathway in regulating epithelial and endothelial barrier function and the application of S1P in barrier dysfunction-related diseases were summarized, so as to provide references for future research.