Abstract： In 1988,Gluckman performed the first cord blood transplant for a 5 year old boy with Fanconi anemia using a cord blood unit from the patient's unaffected sister.1 Patient remains alive and disease free for 24 years.Since then,extensive researches have established the safety and efficacy of umbilical cord blood transplantation (CBT) in both children and adults with a variety of malignant and non-malignant diseases.As of 2011,more than 25 000 CBTs have been performed.Compared with the unrelated bone marrow (UBM) or peripheral blood stem cells (UPBSC),unrelated cord blood (UCB) has many theoretical and clinical advantages:(1) non-invasive and easy procurement,with little risk to the mother or newborn;(2) expands donor pool for minorities targeted;(3) induces less frequent and less severe acute and chronic graft-versus-host disease (GVHD).These properties lead to less stringent HLA matching required;(4) availability for immediate access and use,according to Barker's report the median time to receiving UCB transplantation is 13.5 days,while the time for UBM is 50 days;2 (5) lower risk of transmitting infections by latent viruses.