Abstract: Objective Constructed recombinant adenovirus vector for the express of small interfering RNA targeting telomeric repeatbinding factor2,i.e.rAd-shRNA-TRF2 and to investi gate the effects of rAd-shRNA-TRF2 on cell proliferation of human breast cancer MCF-7 cells．Methods Constructed recombinant adenovirus vector (rAd-shRNA-TRF2) expressing siRNA -TRF2 was constructed by selecting, siRNA witch can specifically and effectively express TRF2 mRNA based on preliminary experiments.After rAd-shRNA-TRF2 was transfected into MCF-7 cells, the cell growth were detected by MTT assay and the cell cycle was observed by means of flow cytometry．Results The cell proliferation of MCF-7 was inhibited.The cell cycle of MCF-7 was at G₀/G₁ phase and the cell proliferation index(PI) was breakdown significantly after rAd-shRNA-TRF2 was transfected into MCF-7 cells．Conclusion The cell proliferation of MCF-7 is prohibited by inhibiting the TRF2 express,which maybe become a new gene therapy strategy for the tumor treatment.