Abstract: Solid tumors cause regional hypoxia when they outgrow the blood supply. The presence of hypoxia cells within the tumor is the primary factor influencing the effect of therapy. Hypoxia imaging agents selectively accumulate in the oxygen deficient organizations or cells that can be detected by the non-invasive methods such as PET and SPECT. It has great practical value in guiding treatment, evaluating efficacy and accessing prognosis. This review briefly introduces the research progress of tumor hypoxia imaging agents.