Fk506 has shown a remarkable anti-rejection activity in experimental and clinical organ transplantation. In the multicenter Japanese studies, the main adverse effects of FK506 were renal impairment, hyperglycemia, hyperkalemia, cardiac symptoms, and abdominal distension. The results of the study concluded that the incidences of adverse effects with FK506 could decrease in the range of FK506 trough levels in whole blood was maintained between 15 and 30 ng/mL during the first 3 months.However, long-term results with FK506 therapy have not been clear, and persistent histologic nephrotoxicity should be avoided. Therefore, we started triple drug therapy (FK506 + azathioprine + prednisone) in April 1996 and performed 16 renal transplant through February 1997.