Objectives To explore the differences in therapeutic efficacy between decitabine combined with low dose HAG(D+ HAG)and CAG in elderly patients with acute myeloid leukemia (AML).Methods Totally 32 elderly patients with AML in our department from July 2012 to July 2015 were retrospectively analyzed.15 patients were on a therapy of decitabine combined with low dose HAG,and 17 patients with CAG.Efficacy and side effects were compared between the two groups.Results In(D+HAG)versus CAG groups,the complete remission(CR)was 10 cases(66.7％)vs.6 cases (35.3 ％),partial remission(PR) was 2 cases (13.3％) vs.1 case(5.9 ％),non-remission(NR) was 3 cases(20％)vs.10 cases(58.8％),and the total efficacy rate(CR+PR)was 80％vs.41.2％ (P＜0.05).The side effects in two groups mainly included bone marrow depression,respiratory tract infection,gastrointestinal reaction,which were all alleviated after symptomatic treatments.The incidence rate of side effects had no statistical difference (P ＞ 0.05).Conclusions The treatment of decitabine combined with low dose of HAG is prior to CAG,and the side effects are all tolerated.So decitabine combined with low dose of HAG can be served as the first-line therapy for elderly AML patients.