Tumor Stem/Progenitor Cells are characterized by undifferentiation/hypodifferention, self-renewal, differentiation potential, which is responsible for tumor occurrence, growth and metastasis. The theory about tumor stem/progenitor cells provides a new insight to recognize the origin and essence of tumors. Gaining a better insight into the origin of tumor stem/progenitor cells and the mechanisms of tumor stem/progenitor cells resistance to chemotherapy may lead to new therapeutic targets and better anticancer strategies. This review summarizes recent progress of research on the origin of tumor stem/progenitor cells and multidrug resistance.