The guidelines for the management of secondary hyperparathyroidism in chronic dialysis patients by Japanese Society of Dialysis Therapy (The JSDT guideline) set the optimal levels of P, Ca and intact-PTH in dialysis patients as 3.5 - 6.0 mg/dL, 8.4 - 10.0 mg/dL, 60 - 180 pg/mL (or whole-PTH 35 - 106 pg/mL) , respectively. Active vitamin D therapy tends to cause the elevation of serum P/Ca levels along with the suppression of parathyroid function. Therefore, it was often difficult to keep P/Ca/PTH within the optimal levels simultaneously by medical therapies. Cinacalcet hydrochloride therapy has a potential to break through the situation since it decreases P/Ca levels while it suppresses parathyroid function.