【Abstract】 Objective To investigate the effects of silencing of OCT4 gene expression by siRNA on the biological behavior of human prostate cancer DUl45 cells and PC3 cells. Methods The siRNA targeting 0ct4 was transfected into DU145 cells and PC3 cells by Lipofectamine 2000(Lipo)，The expression levels of OCT4 was examined by RT-PCR and Western boltting.The change of proliferation was detected by CCK-8. The activities of motility and invasion were assessed by transwell chamber invasion assay in vitro. Results The expression levels of OCT4 mRNA and protein in the cells transfected with siRNA were significantly lower than in blank group and in negative control(NC) group (P<0.05).The proliferation of DUl45 cells and PC3 cells was significantly inhibited and the invasion of the two cell groups was decreased after transfected by OCT4 siRNA(P<0.05).Conclusin The inhibition of OCT4 expression by siRNA could inhibit cell proliferation and decrease the invasion in DUl45 cells and PC3 cells which suggest that OCT4 play a vital role in the gliomagenesis and development of prostate cancer.