Abstract: Tumor stem cells are thought to sustain tumor proliferation, chemoresistance and recurrence after therapy.The chemoresistance of tumor stem cells are due to their stem cell properties.Bmi-1 gene plays an important role in self-renewal and proliferation of stem cells, and is associated with a number of malignancies.Bmi-1 gene is reported to display chemoresistance through upregulation of ABC-transporter family, inhibition of cell apoptosis and many other mechanisms.In this review, we make a summary of research advancement on the relationship between Bmi-1 gene and multi drug resistance.