OBJECTIVE: To study tanshinone ⅡA inhibiting the proliferation and migration induced by homocysteine (Hcy) of rat aortic vascular smooth muscle cells (VSMCs) and its signal pathway. METHODS: VSMCs were selected for the following experiments. In order to validate TanshinoneⅡA inhibiting the proliferation and migration induced by Hcy of VSMCs, VSMCs were divided into control group, Hcy group (1 000 μmol/L), TanshinoneⅡA low-dose, medium-dose and high-dose groups (5, 10, 20 μg/L). In mechanism study test, VSMCs were divided into control group, TanshinoneⅡA group (20 μg/L), rapamycin group (20 nmol/L), MHY1485 group (10 μmol/L), TanshinoneⅡA+rapamycin group (TanshinoneⅡA,20 μg/L+rapamycin, 20 nmol/L), TanshinoneⅡA+MHY1485 group (TanshinoneⅡA,20 μg/L+MHY1485, 10 μmol/L). In validation test of P70S6K and p-P70S6K pathway expression, rapamycin and MHY1485 were used for inhibitory test and activation test, respectively. The proliferation of VSMCs was determined by ELIASA, and Transwell chambers and wound healing test were employed to test the migratory ability of VSMCs. Western blotting were used to investigate the expressions of P21, P27, MMP-2, MMP-9, P70S6K and p-P70S6K in VSMCs. RESULTS: In validation test, compared with control group, 24, 48 h absorbance, migration area, the number of VSMCs penetration and the expression of MMP-2, MMP-9 and p-P70S6K increased significantly, while the expression of P21 and P27 decreased significantly (P<0.01). Compared with Hcy group, 48 h absorbance of TanshinoneⅡA low-dose group, 24, 48 h absorbance and the expression of MMP-2 of TanshinoneⅡA medium-dose and high-dose groups, migration area, the number of VSMCs penetration, the expression of MMP-9 and p-P70S6K in low-dose, medium-dose and high-dose groups all decreased significantly; the expression of P21 and P27 increased significantly in TanshinoneⅡA medium-dose and high-dose groups (P<0.01); there was no statistical significance in P70S6K level among those groups (P>0.05). In cell pathway test, compared with control group, 24, 48 h absorbance, migration area and the number of VSMCs penetration decreased significantly in TanshinoneⅡA group and rapamycin group, while 24, 48 h absorbance increased significantly in MHY1485 group (P<0.01). Compared with TanshinoneⅡA group, 24, 48 h absorbance decreased significantly in TanshinoneⅡA+rapamycin group, while 12, 24, 48 h absorbance, migration area and the number of VSMCs penetration increased significantly in TanshinoneⅡA+MHY1485 group (P<0.01). In inhibitory test, compared with control group, the expression of p-P70S6K decreased significantly in TanshinoneⅡA group (P<0.01); compared with TanshinoneⅡA group, the expression of p-P70S6K decreased significantly in rapamycin group and TanshinoneⅡA+rapamycin group (P<0.01); in activation test, the expression of p-P70S6K decreased significantly in TanshinoneⅡA group (P<0.01), compared with TanshinoneⅡA group, the expression of p-P70S6K increased significantly in MHY1485, TanshinoneⅡA+MHY1485 group (P<0.01). CONCLUSIONS: TanshinoneⅡA can inhibit the proliferation and migration of VSMCs by suppressing mTOR/P70S6K signal pathway.