Abstract: Serum ferritin (SF) was determined in 112 petients with breast cancer postoperation,and the dynamicobservation was made in part of them,the result showed:SF wasno higher in the patient who had not tumours focus of clinic visible,SF value in the patient who had the turmours focus of clinic was higher than the normal contrast groupand the patient who had not tumours focus. SF value of the patient who had transfer ininternal organs of bone was higher than that the patient who recurred in part or transformed in plain lymph. In the patients of dynamicobservation,SF value was higher laterthe cancer transfer than that thd before,and SF vaule was not to change in the patintwhose tumour had not transfre. It is suggested that there is a reference value of SF determination in supervise for resurrention and transform of the breast cancer postoperation.