Abstract： Objective To investigate the prognostic factors in acute myeloid leukemia subtype M2 (AML-M2) patients with chromosome translocation of 8 and 21. Methods By using G-banding analyses karyotype and combining the clinical data, prognostic factors in 94 cases of de novo adult AML-M2 in our hospital from 2001 to 2007 were retrospectively analyzed. Results Chromosome 8 and 21 translocation were identified in 53.2 % (50/94) of AML-M2 cases. In the patients with other aberrations in addition to t(8;21), their complete remission (CR) rates, overall survival (OS) was lower than the patients with sole t (8;21) and normal karyotype(P <0.05). And the patients with sole t (8;21) whose CR rates and OS had no difference with patients with normal karyotype (P>0.05). The patients were divided into 3 subgroups (low index, less than 2.5;intermediate index, 2.5-20;high index, 20 or more) according to WBC index. The CR had no difference among the 3 subgroups, but the OS of the 3 subgroups was different (P<0.05). The OS in the lowest index group was longer than that in the others. Conclusion Cytogenetically, 53.2% cases had chromosome 8 and 21 translocation, 46 % cases had t(8;21) with additional chromosomal abnormalities, and the main additional abnormalities were loss of a sex chromosome (LOS). t(8;21) AML-M2 patients with additional chromosome abnormalities had low complete remission rate and shorter survival time, and its prognosis was poorer. WBC index have no influence on complete remission rate but effected the survival time.