With the progress of medical technology, the development of new drugs and the improvement of the therapeutic effect of graft-versus host disease in the last two decades, the outcomes of allogeneic hematopoietic stem cell transplantation(allo-HSCT) have been greatly improved. However, graft failure is still a rare but serious complication of allo-HSCT. HLA incompatibility, virus infection, elderly donor, uncontrolled primary disease, damage of bone marrow hematopoietic microenvironment, ABO blood group incom...