The important function of iron as a necessary nutrition element in mammals is more and more recognized by people. The normal physiological level of iron is ensured by the rigid regulation mechanism of iron metabolism in animals. Various clinical diseases are induced by iron disorder, like iron deficiency and iron overloading in the body. The current study showed that Hepcidin may be a key factor to control intestinal iron absorbing and regulates iron homeostasis, and may be an important regulating hormone of iron metabolism. It was summarized in this paper that the physiological functions, iron deficiency diseases, for instance iron deficiency anemia and neural diseases of children, and iron overload diseases, such as liver damage, cardiovascular diseases, Parkinson's disease, and cancers etc. And it was expected how to develop the therapy of iron disorder diseases in gene level use modern techniques.