Abstract: Myelodysplastic syndromes （MDS） are clonal hematopoietic disorders characterized by ineffective hematopoiesis, marrow dysplasia and high risk of transforming into acute myelogenous leukemia （AML）. Allogeneic hematopoietic stem cell transplantation （Allo-HSCT） is currently the only method to cure MDS, especially for high-risk MDS patients. However, whether pre-transplantation chemotherapy or not is the most controversial topic among the blood academia. Regarding to this subject, we conclude that pre-transplantation chemotherapy can help the patients gain best benefits, referring to the extensive literatures and our clinical experiences.