Objective:To research the effect of Bmi-1 gene on glioma cells apoptosis. Methods:Bmi-1 gene in U251 glioma cells is silenced by siRNA, and the effect was detected by RT-PCR, the apoptosis condition was detected by flow cytometry, and one way ANOVA and t test were used for statistics analysis. Results:Gel electrophoresis strip of Bmi-1 mRNA in RNA interfered U251 cells is weakly positive, those of negative controls and non-disposals are strongly positive. The gray scale ratio is statistically analyzed, and the difference between RNA interfered cells and non-interfered cells was significant. RNA Interfering may significantly down-regulate the expression of Bmi-1 in U251 cells The apoptosis rate of(32.53±6.33)% in interfered U251 cells is higher than that of(21.91±5.63)% in controls, and the difference is significant statistically. Conclusion:The Bmi-1 gene expression could inhibit the apoptosis of glioma cells and promote the genesis and development of glioma.