Objective:To study the inhibitory effect of tetrandrine(TET) on the level of miR-21 on epithelial-mesenchymal transition(EMT)in ovarian cancer. MethodsHuman ovarian cancer A2780 cells, ES-2 cells and normal human ovarian epithelial IOSE80 cells were used as the research objects, MTT method was used to determine the effects of 0,1.0,2.0,5.0,10.0,20.0 μmol/L TET on the proliferation of three kinds of cells. The experiment was divided into IOSE80 cell control group, A2780 cell control group, ES-2 cell control group, A2780 cell group with TET, ES-2 cell group with TET. The expression level of miR-21 was measured by real-time quantitative PCR(RT-qPCR). The effects of TET on cell migration and invasion were studied by migration and invasion experiments, and the expressions of GSK3β, p-gsk3β, β-Catenin, E-cadherin, N-cadherin and vimentin were measured by Western blot.  Results:Compared without TET, the survival rates of A2780 cells and ES-2 cells decreased significantly with the increase of TET concentration(P<0.05)when TET concentration was 1.0~20.0 μmol/L, the concentrations of TET on A2780 cells and ES-2 cells were 5.0 μmol/L and 3.0 μmol/L respectively for the follow-up experiments. Compared with IOSE80 cell comtrol group, the expression level of miR-21 in A2780 cell control group and ES-2 cell control group increased significantly (P<0.05). Compared with the A2780 cell control group and ES-2 cell control group, the miR-21 expression level, migration ability, invasion ability, GSK3 protein phosphorylation level, β-Catenin protein expression level, N-cadherin protein expression level and vimentin protein expression level in the A2780 cell group and ES-2 cell group were significantly reduced(P<0.05), and the expression level of E-cadherin protein increased significantly(P<0.05).  Conclusion:TET may block Wnt/β-catenin signaling pathway and inhibit EMT of ovarian cancer by down regulating miR-21 expression.