Objective To investigate the etiology of adult iron deficiency anemia and prevention measures.Methods Retrospective analysis of our hospital 156 patients with iron deficiency anemia.History by asking routine examination fiber endoscope,B-ultrasound,imaging,pathology and other tests as specific as possible.Results Of 156 cases the cause of iron deficiency anemia are gastrointestinal diseases,menorrhagia,hypothyroidism disease,cancer,thrombocytopenia and so on.Conclusion Gastrointestinal disease of the important factors in adult non-iron intake of iron deficiency anemia,menorrhagia and other gynecological diseases is for second largest factor,iron deficiency anemia in adult in find the cause as soon as possible to identify and effective treatment to prevent or avoid iron deficiency anemia.