Objective To investigate the effect of gene silencing of Y-box binding protein-1(YB-1) by RNA interference on the proliferation and migration in prostate cancer cells lines PC-3 cells .Methods YB-1 siRNAs(pGenesil-1-YB-1-1 and pGenesil-1-YB-1-2) were synthesized and transfected into cloned into the the PC-3 cells by liposome .The expressions of YB-1 were measure by RT-PCR and Western blotting .The proliferation and migration were respectively detected by MTT and Transwell method . Results ThemRNA and protein expressions of YB-1 were significantly decreased by pGenesil-1-YB-1-1 and pGenesil-1-YB-1-2 (P<0 .05) ,compared with the control group ,the inhibition ratio of mRNA expression was 36 .23% and 39 .42% respectively and the inhibition ratio of protein expression was 41 .56% and 55 .33% respectively .The proliferation and migration were significantly decreased by pGenesil-1-YB-1-1 and pGenesil-1-YB-1-2(P<0 .05) .Conclusion YB-1 gene silencing by RNA interference inhibits the proliferation and migration in prostate cancer cells lines PC-3 cells .