Objective To determine whether Tanshinone ⅡA(Tan ⅡA)has an effect on angiotensin Ⅱ(Ang Ⅱ)-induced prolifera-tion and migration of vascular smooth muscle cells(VSMCs),phenotypic switching,or autophagy.Methods In this study,murine aortic smooth muscle cell lines were treated with Ang Ⅱ to establish a model of cell proliferation.Different concentrations of Tan ⅡA were added and effects on cell proliferation and migration were determined by cell counting using a CCK-8 assay and a cell scratch assay,respectively.Alpha-smooth muscle actin(α-SMA),a marker of contractile VSMCs,was detected by Western blotting.Expression levels of osteopontin(OPN)and the autophagy-related proteins(p62,Beclin-1,LC3A/B)were assayed to determine the effect of Tan ⅡA on VSMC phenotypic transformation and autophagy.Cells were treated with the autophagy inhibitor 3-methyladenine(3-MA),combined with Tan ⅡA,and then cell proliferation,migration and expression levels of phenotypic markers and autophagy-related proteins were assessed.Results After Ang Ⅱ treatment,the proliferation and migratory capacity of VSMCs was significantly enhanced,and phenotypic transformation was sig-nificantly inhibited by Ang Ⅱ.Western blotting revealed that Ang Ⅱ reduced the expression of α-SMA,increased the expression of OPN,p62,Beclin-1,and LC3A/B,and that these effects increased with higher Tan ⅡA concentrations.After the addition of 3-MA to the treated cells,the proliferation and migration of VSMCs induced by Ang Ⅱ was inhibited,the expression of α-SMA was increased,and the expres-sion of OPN,p62,Beclin-1,and LC3A/B was decreased,which was consistent with the effect of Tan ⅡA.Conclusion Tan ⅡA may have inhibitory effects on phenotypic transformation,proliferation,migration,and autophagy of Ang Ⅱ-treated VSMC,suggesting that the inhi-bition of the proliferation and migration may be regulated by autophagy.