Hypoxia remains a major characteristic of tumors. Malignant cell growth requires the presence of a local vascular network that supplies oxygen and nutrients. However，a highly proliferating mass of tumor cells develops faster than the vasculature and rapidly meet up with anavascular environment deficient in oxygen. Hypoxia affects a variety of cell properties such as cellgrowth，apopfosis，metastasis and sensitivity to treatment. Nevertheless，the responses of cells tohypoxia are essential questions in understanding tumor progression，which may lead to novelstrategies for diagnosis and treatment. microRNAs (miRNAs) are about 22 nucleotide RNAmolecules that participate in a wide variety of physiological and pathological cellular processes such as cell differentiation，proliferation，death，metabolism and more recently tumori genesis Recent studies have established a link between a distinct miRNAs expression profile with hypoxiaand global miRNAs expression changes have been described and in some cases shown to correlatewith the clinicopathological features of the tumor. However，there is still few mechanism has been proposed to date and relatively little is known about miRNAs regulation in hypoxia.