Thalassemia can be treated by preserving umbilical cord blood, which can be used to treat thalassemia if the leukocyte antigens in the hematopoietic stem cells are compatible. The onset of thalassemia is related to heredity, and common classifications include alpha thalassemia and beta thalassemia. Generally, no special treatment is needed for thalassemia of stationary type or mild type; if it is intermediate type or severe type, treatment is needed, and common treatments include hematopoietic stem cell transplantation, red blood cell transfusion, splenectomy, gene activation therapy, iron chelating agent, etc. Among them, allogeneic hematopoietic stem cell transplantation, gene activation therapy, iron chelating agent, etc. can be used. Among them, allogeneic hematopoietic stem cell transplantation is the current cure for beta thalassemia major. There are hematopoietic stem cells present in umbilical cord blood, which can be used as the first choice of treatment if their leukocyte antigens are compatible. Therefore, if the fetus is diagnosed with possible thalassemia during pregnancy, the cord blood can be preserved for treatment.