Hypoxia inducible factor 1α (HIF-1α) participates in several biological processes of cancer, such as proliferation, apoptosis, invasion and metastasis, through regulating its target genes and self-expression, and its overexpression predicts the poor prognosis of the cancer. Epithelial-mesenchymal transition (EMT) plays an important role in tumor invasion and metastasis, and its mechanism involves complex signaling pathways, E-cadherin, Snail transcription factor, microRNA and so on. This paper reviews the role and significance of HIF-1α and EMT in tumor progression.