Abstract: Objective: To construct an adenovirus vector expressing the soluble extracellular domain of TGF-β RⅡ and to evaluate the function of the vector. Methods: The soluble extracellular domain of the murine TGF-β RⅡ gene was cloned by RT-PCR and inserted into an adenovirus vector using the AD-easy XL Adenovirus Vector System. Western blot showed that eukaryotic cells containing the vector expressed the soluble extracellular domain of TGF-β RⅡ. The presence of the soluble extracellular domain of TGF-β RⅡ was detected using an ELISA, and the anti-cancer effect was evaluated by tumor inhibition tests in vivo. Results: The soluble extracellular domain of the murine TGF-β RⅡ gene was successfully cloned into an adenovirus vector. Functional tests showed that the soluble extracellular domain of TGF-β RⅡ could block TGF-βsignaling in vitro after infecting eukaryotic cells with the newly constructed adenovirus vector. Tumor inhibition tests showed that the adenovirus vector containing the soluble extracellular domain of TGF-β RⅡ could inhibit tumorigenesis in mice. Conclusion: Expression of the soluble extracellular domain of TGF-β RⅡ improved the anti-cancer immune response and inhibited cancer progression. Using a construct such as this vector provides a potential newtreatment option.