Objective : To study the relationship between lncRNA SIL and proliferation and migration of alveolar epithelial cell during pulmonary fibrosis. Methods : The expression level of lncRNA SIL in A549 cells induced by transforming growth factor(TGF⁃ β1) was detected by RNA fish. The eukaryotic expression vector of lncRNA SIL was built and transfected into A549 cells , the proliferation and migration of the cells after overexpressing lncRNA SIL were studied by RT⁃PCR , MTT , Western blot , cell damage repair experiments and immunofluorescence. Result: The migration and proliferation of A549 cells were significantly reduced compared with the control group after transfected by lncRNA SIL. When lncRNA SIL was overexpressed in A549 cells , cell proliferation , migration and expression of proliferation - related proteins PCNA and Ki67 were decreased compared with the control group. Analysis of the expression of cellular marker proteins showed that , the expression levels of interstitial cell marker proteins α ⁃SMA and Collagen⁃1 were significantly reduced , while the expression level of alveolar epithelial marker protein E. cad significantly increased. Conclusion LncRNA SIL can inhibit the proliferation and migration of A549 cells , and also can inhibit EMT induced by TGF⁃ β1 .