Abstract： Objective To evaluate the efficacy and safety of mizroribine (MZR) in early postoperative renal transplantations.Methods A single center, perspective, randomized and controlled clinical study was performed on 61 renal transplant recipients.Forty-eight after operation,patients were randomized into 2 groups as follows:(1) MZR group:33 cases of renal transplant recipients were administrated orally with MZR combined with tacrolimus and prednisone; (2)mycophenolate (MMF) group:28 cases were administrated with MMF combined with tacrolimus and prednisone.The dose of MZR was 150 mg for the weight under 50 kg and 200 mg for the others.The dose of MMF was 1.5～2.0 g/d for the weight above 70 kg,1.5 g/d for 50～70 kg and 1.0 g/d for ＜50 kg.The dose of tacrolimus was 0.1 ～0.15 mg· kg-1 ·day-1.All the patients were given 20 mg basiliximab as induction therapy 2 h preoperation and 4 days post-operation.Acute rejection incidence,renal graft survival rate,morbidity of hyperuricemia,marrow depression,cytomegalovirus infection and severe gastrointestinal side effects were analyzed during a follow-up period of 6 months.Results Acute rejection incidencein two groups was 15.2％ and 10.7％ respectively,and graft survival rate was 97.0％ and 89.3％ respectively.There were no significant differences in acute rejection incidence and renal graft survival rate between two groups.There were also no significant differences in the morbidity of hyperuricemia,marrow depression and gastrointestinal side effects between two groups.Although there were no significant differences in infection morbidity between two groups,more cytomegalovirus infection recipients were observed in the MMF group.Conclusion It demonstrated that under the intensive monitoring,MZR was safe and effective for renal transplant recipients.