Abstract: Erythropoietin is an endogenous 34 000 glycoprotein hormone composed of 165 amino acids. EPO is mainly derived from the liver of the fetus and synthesized in the kidney after birth, but is secreted by the liver, kidney, brain, reproductive system, bone marrow macrophage and mammary gland. The production of EPO is regulated by hypoxia-inducible factors. EPO can significantly stimulate the proliferation and survival of red blood cells and promote hematopoiesis; it has been used clinically to treat chronic renal anemia, anemia caused by bone marrow tumors and myelodysplasia. EPO has a wide range of physiological functions and it is found in all systems of animal life. Apart from promoting hematopoiesis, EPO also promotes angiogenesis, and shows brain protection, kidney protection, heart protection, regulation of metabolism, regulation of inhalation, protection of the digestive system and reproductive system. Animals without EPO can hardly survive. It illustrates that EPO plays an important role in life.

Key words: erythropoietin, generative site, regulation, physiological function