This study was aimed at the high incidence of aGVHD, especially severe aGVHD in thalassemia major URD-HSCT. Basiliximab was added to the original prevention program. The aGVHD incidence, implantation rate, transplant-related mortality, infection incidence would be observed. It is hopeful to reduce the aGVHD incidence after URD-HSCT and promote curative effect.