Abstract： AIM To detect the expression of molecules of the renin-angiotensin system (RAS) in hepatocellular carcinoma (HCC) and explore whether angiotensin Ⅱ (Ang Ⅱ) induces epithelial-mesenchymal transition (EMT) in SSMC7721 cells.METHODS Fifty-six HCC tissues were collected,and imrnunohistochemistry and Western blot were used to assess the expression of angiotensin converting enzyme 1 (ACE1),ACE2,vimentin,E-cadherin proteins in these tissues.Ang Ⅱ was then used to stimulate SSMC7721 cells to detect whether EMT markers such as vimentin and E-cadherin were induced.RESULTS Compared with normal tissues,the expression of ACE1 and AT1 in HCC tumor tissues were higher.Ang Ⅱ up-regulated the expression of vimentin but down-regulated the expression of E-cadherin in SSMC7721 cells.CONCLUSION The RAS may play a role in HCC metastasis.