Objective To investigate the characteristics of the abnormal karyotype and normal karyotype with myelodysplastic syndrome(MDS).Methods A retrospective analysis of 131 MDS patients was conducted.The cell morphology between abnormal karyotype and normal karyotype was compared.Results Of 131 MDS patients,71 cases (56.5％)had clonal chromosomal abnormalities.Pelger nuclear myeloid and lymphoid small megakaryocytes in abnormal karyotype group was significantly higher than the normal karyotype group (P ＜ 0.05).Megaloblastic erythroid-like change,double-nucleated red blood cells,multinucleated red blood cells,the petals nuclear,nuclear fragmentation;the myeloid uneven particle distribution,nuclear pulp imbalance,megaloblastic degeneration,vacuoles,AUER,dual-core; single-round,multi-roundnuclear megakaryocytes,the two groups showed no significant differences (P ＞0.05).Conclusion Pelger nuclear myeloid,lymphoid small megakaryocytes had significantly higher incidence of abnormal karyotype MDS compared with normal karyotype cell dysplasia,there was some correlation between abnormal karyotype and cell morphology.