【Abstract】Backgroud Most of patients with long-term hospitalization of intensive care unit (ICU) will exist in varying degrees of anemia . The kind of anemia caused by the examination and treatment measures was referred to as ‘iatrogenic anemia ’.Iatrogenic anemia ofen requires blood transfusion therapy,but allogeneic blood transfusion often have adverse effects associated with transfusion which has an adverse effect on the prognosis of patients.Objective Understand the iatrogenic anemia and its reaserch progress.Content The status,causes,harm and prevention strategies of iatrogenic anemia was reviewed.Trend Do preventive intervention on iatrogenic anemia, minimize allogeneic blood transfusion on the basis of the essential treatment in patients and improve the prognosis.