Acute myeloid leukemia (AML) is the most common hematological malignancies in adult patients with leukemia, and t(8;21) AML accounts for a substantial proportion of AML. AML patients with t(8;21) possess a favorable outcome and 3 - 4 course high dose cytarabine (3 g/m2) is the standard consolidation therapy for these patients with a 5-year overall survival approximately 60%. In China, intermediate dose cytarabine (1 - 2 g/m2) is used for consolidation therapy due to toxicities. After 3 - 4 course cytarabine consolidation, maintenance therapy is performed with conventional chemotherapy with a 5-year overall survival approximately 60% as well. However, continuous chemotherapy may cause toxicities and inhibit patients' immune response. Exploring new drug for maintenance therapy is urgently needed. Decitabine has a potent ability to inhibit proliferation and induce apoptosis of AML1-ETO positive leukemia cell line. Furthermore, the immunomodulatory effect of decitabine was also reported by several studies. In this study, the investigators plan to carry out a prospective, multicenter, randomized, controlled trail to compare decitabine versus conventional chemotherapy for maintenance therapy of patients with AML with t(8;21). Results of this trial may optimize the treatment for AML patients with t(8;21) in the setting of intermediate dose cytarabine consolidation.

Inclusion Criteria:

1. Patients are adults age ≥18 and ≤60 years
2. Patients are diagnosed as AML with t(8;21)
3. Continuous complete remission after induction and consolidation therapy with 3 - 4 course high dose cytarabine (2 g/m^2)
4. Patients whose aspartate transaminase (AST)/alanine transaminase (ALT) are ≤ 2.5 times higher than the normal upper limit, total bilirubin ≤ 3.0 mg/dl, and serum creatinine ≤ 2.0 mg/dl.
5. Subjects that signed the informed consent, which indicated they understood the purpose, the procedure and potential benefits of the trial and were willing to participate in the trial.

Exclusion Criteria:

1. Pregnant or lactating women.
2. ECOG performance status score > 2.
3. Patients are candidates for hematopoietic stem cell transplantation.
4. Patients with a history of use of azacitidine or decitabine.
5. Patients with mental or other disorders that cannot completely cooperate with the treatment or follow up.
6. Subjects that were allergic to decitabine vehicle.
7. Patients receive immunotherapy.
8. Patients also have other organ malignant tumor.
9. Participating in other clinical research in the same period.
10. The researchers estimate that patients cannot enter the clinical trial.