The key factor affecting URD-HSCT's success is GVHD. Thus effective prevention and treatment of GVHD is a prerequisite to ensure a successful transplant. CD25 is a humanized monoclonal IgG1,with murine anti-human IL-2RA chain complement determining region retained. IL-2RA chain expressed only on the surface of activated cytotoxic T cells, which could convert the IL-2R complexes into a higher affinity. The feature that IL-2RA distributes only on the surface of activated lymphocytes indicates it's a ideal target when designing the policy to scavenge antigen-specific allogeneic reactive T cells. In vitro experiments, CD25 monoclonal antibody binds specifically with IL-2RA+ cells by inhibiting IL-2 binding to its receptor competitively. Basiliximab has now been used as first-line medication for aGVHD treatment, as well as the combined prevention of hematologic malignancies URD-HSCT treatment . However as for thalassemia major URD-HSCT, few cases have been reported.