〔Abstract〕 Objective To study the effect of sirtuin-2(SIRT2) on proliferation and migration of human breast cancer MDA-MB-231 cells. Methods Real-time fluorescence quantitative PCR(qRT-PCR) was applied to detect SIRT2 mRNA expression in breast cancer MDA-MB-231 cells. MDA-MB-231 cells were transfected with small interference RNA(siRNA), targeting SIRT2 in the experimental group, and also with negative control sequence in the control group. The proliferation ability of MDA-MB-231 cells was detected by MTT assay and cell colony formation assay, and the migration abilityof MDA-MB-231 cells was assessed through wound healing assay. Results The expression of SIRT2 mRNA in MDA-MB-231 cells transfected with SIRT2-siRNA was lower than that in the negative control group(P<0.01). After transfection with SIRT2-siRNA, cell proliferation, clonality and migration of MDA-MB-231 cells decreased(P<0.05). Conclusion The proliferation and migration of breast cancer MDA-MB-231 cells were inhibited after SIRT2 knockdown, which suggested that SIRT2 might function as an oncogene in triple negative breast cancer cells.