Cord blood offers many advantages including a high concentration of hematopoietic stem cells, a large number of potential donors, and ease of harvest. Furthermore, since there is no risk for either the mother or baby, few people refuse to donate. There is thought to be a low risk for virus contamination and also probably a low incidence and severity of GVHD. Cord blood can be obtained quickly without the assistance of a coordinator and one or 2 locus-mismatched HLA is usually acceptable. In Japan, there are 10 cord blood banks supported by the government. Between 1996 and June 2002, 9,500 units were registered with the Japan cord blood bank network (JCBBN). 630 units were delivered and most of these were transplanted. The status of registered cord blood units worldwide is shown. 59,081 units have been registered by NETCORD. The Japan cord blood bank network accounts for 13% of these units. I will discuss the Tokyo cord blood tank (TCBB). The bank at Tokyo, to which we belong, is one of the largest banks in Japan. We helped to establish Asia CORD in 2000 and have held annual conferences and meetings in Tokyo to exchange information. So far, China, Korea, Taiwan, Thailand, Viet Nam and Japan have participated. We accepted three trainees from the Ho Chi Minh City Blood Transfusion and Hematology Center for training in cord blood transplantation in May 2001. In January 2002, a patient with ALL received cord blood and was successfully engrafted at Ho Chi Minh City Blood Transfusion and Hematology Center. We present here the clinical outcome of these patients through Tokyo cord blood bank and Japan cord blood bank network. First, the number of CB units stored and registered at JCBBN and TCBB has increased rapidly over the past two years. Second, the survival rate of acute leukemia patients in release was significantly lower than that in patients in CR. Third, the engraftment rate in patients with metabolic disease (50%) was lower than that in patients with leukemia. Fourth, there was no significant difference in the incidence of acute GVHD greater than grade II between patients with a 1-locus and 2-locus mismatch. Finally, the incidence of acute GVHD was relatively low, and there were no deaths related to acute GVHD.