Iron supplement is standard and important in renal anemia therapy. In renal anemia study in Taiwan, iron supplement is suggested if ferritin less than 300 ng/mL or transferrin saturation less than 30% in patients of chronic kidney disease. For those already with iron therapy, ferritin was suggested to keep in the range of 300-500 ng/mL and transferrin saturation in the range of 30-50%. No large-scale and long period clinical trial investigating efficacy of protocolized iron supplement algorithm was found in the past. In the hemodialysis unit of National Cheng Kung University Hospital, use of iron supplement algorithm could decrease erythropoietin dosage, stabilize dialysis patient hemoglobin, increase patient percentage in adequate hemoglobin range, and further improve renal anemia treatment.