Objective:To explore the safety and advantages of non-cryopreserved sibling umbilical cord blood hematopoietic stem cell transplantation for major thalassaemia in children.Methods:From October 2016 to June 2021, 9 patients with major beta thalassaemia received non-cryopreserved hematopoietic stem cell transplantation of sibling umbilical cord blood at Zhongshan Hospital of Xiamen University. The pretreatment scheme, the process of stem cell implantation and follow-up were analyzed and summarized.Results:Among the 9 cases, there were 5 males and 4 females with a median age of 4(2~11)years. Median level of ferritin was 2 997(1 936~5 512)μg/L. At gestational weeks 12~16, each patient's mother underwent villi testing to confirm that the donor without thalassaemia major was complete HLA-matched with the patient. All of them received an intensive conditioning regimen made up of cyclophosphamide(CTX), fludarabine and busulfan(Bu). Graft-versus-host disease(GVHD) was prevented by cyclosporine A(CSA)and mycophenolate mofetil(MMF)with or without methotrexate(MTX). Except for one failed implant, 8 cases were successfully engrafted. Median time of neutrophil implantation was 19.5(15~26)days, median time of platelet implantation 32(22~34)days and median time of erythrocyte implantation 30.5(18~37)days. Up until September 1, 2021, the median follow-up period was 27(3~59)months and the rate of successful engraftment 88.89%. There was no transplant-related mortality. Overall survival was 100% and thalassaemia-free survival 88.89%. Two patients developed grades Ⅱ skin acute GVHD(22.2%). No grade Ⅲ-Ⅳ GVHD or chronic GVHD occurred. Epstein-Barr virus infection occurred in 1 case.No infection of cytomegalovirus occurred.Conclusions:For major thalassaemia in children, stem cell transplantation of non-cryopreserved sibling cord blood is both safe and feasible with a high implantation rate and a low incidence of GVHD.