The purpose of this study is to determine whether the escalation dosage of Daunorubicin and cytarabine is effective and safety in the treatment of older adult Chinese acute myeloid leukemia（AML） patients aged 55 to 65 years.

the DA 3+7 regimen is the standard therapy in the AML treatment.Escalated dosage of daunorubicin in induction therapy is reported effective and result in a more rapid response and a higher response rate than does the conventional dose, without additional toxic effects in elderly AML patients between 60 to 65 years.Higher Overall survival rate and Event-free survival rate was obtained in escalated group compared with conventional dose. We are wondering if Chinese older AML patients can benefit from this escalated induction regimen.

High dose cytarabine in AML consolidation is reported improving the survival of elderly AML patients than the conventional dose，but it is not determined in Chinese older adult AML patients.

Inclusion Criteria:

• primary AML（except APL patients）;
• ECOG PS:0-2

Exclusion Criteria:

• AML patient who has already received induction treatment, no matter what the outcome is;
• Treatment-related AML;
• Active cancer patients who's condition need to be treated;
• The one with serious infectious diseases（eg.uncontrolled tuberculosis or invasive pulmonary aspergillosis）
• Active heart disease.