【Ａｂｓｔｒａｃｔ】　Background　There are many different kinds of oxygen sensors and molecular mechanisms of response to hypoxia in the body to maintain the oxygen homeostasis， which can reduce or avoid damages caused by dramatic changes of partial pressure of oxygen（PO2）. More and more attentions have been paid on these issues.　Objective　To summarize the known oxygen sensors and the advances in the mechanisms of response to hypoxia and signal transduction.　Content　Our review elaborates the different kinds of oxygen sensors， the mechanisms of response to hypoxia and signal transduction in detail.　Trend　The mechanisms of oxygen sensing and signal transduction are very complicated， further in-depth study will be very important in the prevention， diagnosis and treatment of hypoxia.