Abstract: Objective To investigate the incidence and distribution of aberrational karyotype in acute myeloid leukemia (AML), and study the significance of the grouping by Southwest Oncology Group/Eastern Cooperative Oncology Group (SWOG/ECOG) in the prognosis of AML Methods The chromosome was prepared with brief culture of bone marrow, and the karyotype was analysed by G banding technique. All the patients were grouped according to the criterion of SWOG/ECOG, and the survival function of different groups was observed by the Kaplan-Meier method.Results 56 (67.47 %) out of 83 patients had clonal chromosome aberrations. Among those 56 patients, AML with translocation (15;17) and with translocation (8;21) presented in 30 patients(53.57 %), and the other kinds of aberrational karyotypes shared the left proportion. Among the 74 followed-up patients, 42 patients were dead. Among three groups with favorable, intermediate and adverse prognosis respectively, there is a significant difference (P <0.001). The complete remission rate of favorable group is higher than that of both intermediate and adverse (P <0.05). There is no difference between intermediate and adverse groups(P>0.05). Conclusion Cytogenetic aberration is one of the important factors affecting the effect on prognosis. The criterion of SWOG/ECOG can predict prognosis objectively.