Abstract: Objective To study the effects of short hairpin in RNA(shRNA) targeting S100A4 on the proliferation and migration potential of breast cancer MCF-7 cells. Methods The S100A4-shRNA expression vector was constructed and confirmed by sequencing. Then the plasmid was transfected into MCF-7 cells via lipofectamine TM 2000, and the changes of S100A4 expression were determined using quantitative RT-PCR and Western blot 48 h after transfection. Flow cytometry and MTT assay were performed to assess the effect of the S100A4-shRNA expression vector followed by G418 selection,colon culture.Migration capability of stably transfected MCF-7 cells in vitro was evaluated by using wound assay. Results S100A4-shRNA expression vector was constructed and transfected into MCF-7 cells.48h after transfection, S100A4 mRNA and S100A4 protein level were decreased significantly. The suppression of S100A4 expression by S100A4-shRNA expression vector inhibited the growth of MCF-7 cells and significantly higher apoptosis cell rate was observed in S100A4shRNA expression vector-transfected cells.The morphology of stably transfected MCF-7 cells didn't change, but the potentiality of migration of MCF-7 cells was decreased significantly. Conclusion S100A4-shRNA expression vector can significantly suppress S100A4 expression and inhibit the proliferation while decreasing the migration capability of MCF-7 cells.