Abstract: The uncontrolled proliferation of tumor cells and the relative deficiency of the internal neovascularization network lead to insufficient oxygen supply. Hypoxia, an important feature of tumor microenvironment, can active the expression of hypoxia-inducible factors(HIFs) and induce the change of a number of miRNAs (microRNAs, miRs) content. miRNA are small, noncoding RNA, regulating gene expression mainly at post-transcriptional level. miR-210 have an important role in the occurrence and development of tumors as the most principal hypoxia-regulated-miRNAs, participating in cell activities such as mitochondrial metabolism, angiogenesis, cell cycle regulation, DNA repair and so on; miR-210 is over-expressed in most tumor tissues and plasma, and correlated with poor prognosis, therefore, miR-210 can be used for tumor screening, diagnosing and predicting the prognosis of patients. With the further study of downstream target gene of miR-210, the target therapy aiming at miR-210-mediated signal pathway provides a broader prospect for the treatment of malignant tumor.