Abstract: 5 q syndrome is a disease of hematopoietic stem cells with more than 90% of the cells from malignant clones, exist in approximately 10-20% of the patients with MDS.The lack of chromosome 5 area contains gene is the basis of 5 q syndrome occurs, Its main clinical manifestation is a macrocytic anemia, hypolobulated megakaryocytes, normal to elevated platelet count,As clinicians diagnostic evaluation for new patients, we have a different understanding in 5 q syndrome,some unusual clinical situations have emerged in our clinical practice. Lenalidomide is considered to be the standardbe to treat low-risk 5 q syndrome, because of its side effects and not all patients have reaction on the Lenalidomide. Therefore, we need new treatments for lack of chromosome 5 patients , now we narrate the 5 q syndrome diagnosis and treatment progress.