Objective:To investigate the effect of Bmi1 on proliferation of rat adult hepatic stem cells. Methods:Bmi1 siRNA was transfected into rat adult hepatic stem cells OC3. Then the expression of Bmi1 in OC3 was detected by real time PCR; the proliferative capability was detected by CCK8; and the cell cycle was detected by flow cytometry 24 h after transfection. Results:The decreased expression of Bmi1 was associated with decreased viability of OC3 cells [inhibition ratio: (20.35±0.132)%] and the number of cells with S phase[(24.48±0.96)%] was decreased significantly. Conclusions:Knockdown of Bmi1 can inhibit the proliferative capability of rat hepatic stem cells.