Abstract:Tumor microenvironment (TME) is composed of tumor cells and interstitial cells that interact with tumor cells.It is a bidirectional, dynamic and complex network between TME and tumor cells.In the interstitial tissue,there are infiltrating immune cells, various cytokines, chemokines, vascular system and so on.The irregular growth kinetics of tumor growing leads to the increased oxygen consumption, in turn, hypoxic conditions inTME.By inducing the production of immunosuppressive cells and inhibiting immune cells with normal effects or activating immune checkpoints ［programmed death receptor-1 (PD-1), programmed death ligand-1 (PD-L1), cytotoxic T lymphocyte associated antigen-4 (CTLA-4)］ and other immune factors, hypoxia and hypoxia inducible factor (HIF-1) in TME can inhibit innate and adaptive immunity and then participate in all aspects of tumor metastasis and immune escape.This article reviews and discusses the role of hypoxia and HIF-1 in tumor immune escape and its regulation in tumor immunity to improve immunotherapy.