Abstract: OBJECTIVE To research the possible molecular mechanisms of FGF21 via TGF-b/Smads signal pathway to delay the development of liver cancer. METHODS Detect the protein expressions of TGF-β1, TGF-β RⅡ, Smad 2,3,4,7 of respective rats cancer tissue with Western blot and detect the mRNA expression of TGF-β1, TGF-β RⅡ, Smad 2,3,4,7 of respective rats cancer tissue with Q-PCR. RESULTS The expressions of TGF-β1, TGF-β RⅡ, Smad 2,3,4,7 varied with the different concentrations of FGF21(P<0.05). CONCLUSION By promoting TGF-β/Smads signaling pathway in the expression of signaling molecules or receptors, or by decreasing the blocking of this signaling pathway, tumor was inhibited by FGF21.