Objective::To screen out the effective components of Salvia miltiorrhiza by establishing an in vitro model of pulmonary epithelial mesenchymal transformation. Method::Different concentrations of salvianolic acid A (10, 20, 40, 80, 160 μmol·L^-1), salvianolic acid B (10, 20, 40, 80, 160 μmol·L^-1), tanshinol (10, 20, 40, 80, 160 μmol·L^-1), tanshinoneⅡ_A (10, 20, 40, 80, 160 μmol·L^-1) and the blank group were applied to A549 cell, cell proliferation and cytotoxicity assay (MTS) were used to detect the proliferation effect of menthol on A549 cells.After screening the safe concentration of the active ingredients of salvia miltiorrhiza by MTS, cells were divided into blank group, model group, salvianolic acid A group, salvianolic acid B group, tanshinol group and tanshinoneⅡ_A.Then, the inhibitory effect of the active ingredients of salvia miltiorrhiza on the proliferation of A549 cells induced by TGF-β₁ was detected by MTS. Enzyme linked immunosorbent assay (ELISA) method to detect salvia miltiorrhiza effective component of fiber protein(FN), collagen type I (COL-Ⅰ) expression. Based on the above results, the active components of salvia miltiorrhiza, which have best inhibition were screened out, and their effects on the expression of E-calcium-viscosity (E-Cad) protein were detected by Western blot. Result::Compared with blank group, salvianolic acid A 40 μmol·L^-1, salvianolic acid B 160 μmol·L^-1, tanshinol 160 μmol·L^-1 had toxic effects on A549 cells (P<0.05). In the non-toxic concentration range, compared with the model group, salvianolic acid A 10, 20 μmol·L^-1, salvianolic acid B 80 μmol·L^-1 showed inhibition effect after 24 h culture (P<0.05). After 72 h culture, salvianolic acid A 5, 10, 20 μmol·L^-1, salvianolic acid B 40, 80 μmol·L^-1inhibition effect was very significant (P<0.01). ELISA results showed that with the blank group, model group cells the expression of FN and COL-Ⅰ increased significantly (P < 0.01). Compare with model group, salvianolic acid A 20 μmol·L^-1, salvianolic acid B 80 μmol·L^-1 inhibited FN and COL-Ⅰ(P<0.05). Western blot results showed that salicylic acid A and salicylic acid B had protective effects on E-Cad (P<0.01). Conclusion::Salvianolic acid A and salvianolic acid B have inhibitory effects on epithelial mesenchymal transformation by TGF-β₁, which may be the main effective components of salvianolic acid in the treatment of pulmonary fibrosis.