Major causes of death in dialysis patients are heart failure, infection, cerebro-vascular accident, malignancy, myocardial infarction, and cardiovascular disturbance; they are 43.7% of all causes of death. Hyperphosphatemia and increased calcium-phosphorus product aggravate ectopic calcification, and raise mortality rate. According to statistical data from the Japanese Society for Dialysis Therapy, calcium and phosphate levels recently decreased, because of progress of therapeutic agents and increase in aged people. But extreme decreases of them are also the risk factors of mortality, so appropriate control into the recommended range is necessary.