In this multi-center, randomized, open-label, prospective clinical trial, a total of 60 relapsed/refractory AML patients will be randomized into 2 groups. Patients in the IAC arm receive the therapy consisting of idarubicin 10 mg/㎡/d on days 1-3, cytarabine 100mg/㎡/d on days 1-7 and cyclophosphamide at a dose of 350mg/㎡/d on the second day and the fifth day. In the control arm, patients received other physician-directed regimen including fludarabine, cytarabine with/without granulocyte stimulating factor(FLA±G) regimen,cytarabine plus daunorubicin(DA）regimen , decitabine,aclacinomycin and cytarabine(decitabine plus AA) regimen or AA regimen plus granulocyte stimulating factor. All the regimen in the control arm can not contain cyclophosphamide. The primary end point is complete remission. The second end points include overall survival, relapse-free survival and time to treatment failure.