Myelodysplastic syndrome（MDS）is a group of myeloid stem cell clonal disorders，characterized by a various degree decrease of peripheral blood cells，ineffective and pathological bone marrow hematopoiesis. There is large variability in the risk of progression to acute myeloid leukemia（AML）. The pathogenesis of the disease become clear gradually：the imbalance of the immune system，especially cellular immune defects，lead to the abnormal cloning clear blocked，abnormal precursor cells immune escape，while a variety of secretion cytokines promote apoptosis of bone marrow cells early. In this article，the changes of natural killer cells，lymphocyte，dendritic cells and marrow-derived suppressor cells of myelodysplastic syndrome and acute myeloid leukemia are reviewed in recent years in order to optimize the monitoring MDS progress.