Abstract: Tumor stem cells play an important role in the occurrence and development of cancer. Sox2 is an important transcription factor of stem cells and its abnormal expression may promote the occurrence and progress of a variety of malignant tumors, besides its potential in maintaining self-renewal and multidirectional differentiation potential of stem cells. The specific mechanism is involved in tumor proliferation, differentiation, invasion, metastasis, and drug resistance, etc. At the same time, Sox2 is closely associated with epithelial-mesenchymal transition, which is an important biological process in malignant tumor cell of epithelial origin gaining the ability of migration and invasion. The studies of Sox2 in the field of cancer research helps to find new clinical treatments.