Donor specific anti-HLA antibody (DSA) is closely related not only to primary graft rejection (GR) after HLA-incompatible transplantation, but also to the occurrence of primary PGF. Desensitisation therapy can reduce the level of DSA in patients and decrease the incidence of PGF after transplantation. However, most studies at home and abroad have focused on DSA levels in recipients before transplantation, risk factors and their effects on prognosis. Very few studies have focused on the rate of DSA positivity and its risk factors after transplantation. Therefore, this project aims to clarify the rate of DSA positivity after HLA-incompatible Allo-HSCT and reveal the influencing factors of post-transplantation DSA positivity with the help of a prospective, registry-based clinical cohort of HLA-incompatible transplant recipients, in order to provide a basis for the prevention and treatment of DSA-induced graft rejection or PGF.