Objective To explore the safety and efficacy of islet cell transplantation through percutaneous trans-hepatic puncture of portal vein for treating type 1 diabetes on pediatric liver transplantation recipients. Methods The clinical data of one type 1 diabetic child undergoing islet cell transplantation after liver transplantation in Tianjin First Central Hospital was analyzed retrospectively. The donor pancreas was digested by injecting collagenase solution combined with neutral protease and the islets were purified using continuous density gradients centrifugation. Cultured islets were infused through percutaneous trans-hepatic portal vein puncture to the liver of a pediatric patient with type 1 diabetes after liver transplantation in Tianjin first center hospital. Theblood glucose，insulin dosage，C-peptide，liver and renal function after transplantation were monitored. After transplantation, the patient was treated with anti-rejection and anticoagulation therapy, the insulin was used according to the blood glucose. Results The yield of high purity islet was 212 073 islet equivalents（IEQ）. Islet viability was 95% while the glucose stimulation index（GSI）was 1.77. The transplant tissue volume was 1 ml. After islet transplantation，the fasting blood glucose of the child patient became stable gradually, and the daily insulin dosage gradually decreased. Exogenous insulin therapy was completely stopped 20 d post islet transplantation with normal fasting C-peptide levels. The patient's liver and renal function was stable while no complications after islet transplantation was observed. Conclusion The islet transplantation is effective and safe for treating children with type 1 diabetes after liver transplantation.