Abstract: Objective To observe the effects of double-stranded small interfering RNA (siRNA) of silent information regulator 1 (SIRT1) on the cell migration and the expression levels of MMP2 and MMP9 of matrix metalloproteinases in prostate cancer DU145 cells. Methods DU145 cells were cultured in vitro and divided into scramble siRNA group and SIRT1 siRNA group randomly. The efficiency of SIRT1 siRNA was examined by Western blot, and the cell migration of DU145 cells was assayed by wound healing, colony formation and transwell migration experiment. The protein expression of MMP2 and MMP9 were determined by Western blot. Results Compared with scramble siRNA group, the protein expression of SIRT1 in SIRT1 siRNA group decreased, and the colony formation and cell migration of DU145 cells were restrained significantly and the expression of MMP2 and MMP9 also decreased. Conclusion The cell migration of DU145 cells can be inhibited by down-regulating the expression of SIRT1, and its mechanism may relate to the changes of the expression of MMP2 and MMP9 in matrix metalloproteinases.