Objective: To study the expression of CD123 in bone marrow (BM) blasts of acute myeloid leukemia (AML) patients to explore the relationship between CD123 expression and therapeutic response and prognosis. Methods: This study retrospectively analyzed expression and distribution of CD123 in BM blasts in 137 cases of newly diagnosed AML (excluded M₃) , CD123 detected by flow cytometry≥20% was defined as positive, including 84 CD123⁺ AML and 53 CD123^- AML, efficacy and prognosis were compared between the two groups. Results: ① Among 137 patients, 84 were in group CD123⁺ (61.3%) , and 53 in group CD123^- (38.7%) . All 137 patients were classified into risk groups based on cytogenetic and molecular biology abnormalities. No significant differences were seen between the three risk groups with regard to their CD123 levels (χ²=0.861, P=0.650) . Compared with CD123^- group, the CD123⁺ group had higher WBC[47.7 (1.0-264.0) vs 22.4 (0.7-211.0) , z=-2.592, P=0.010]. ② The rates of first complete remission (CR1) and recurrence of CD123⁺ group were 54.8% (46/84) and 50.8% (32/63) , respectively; and CD123^- group were 73.6% (39/53) and 41.7% (20/48) , respectively. There was significant difference of CR1 between the two groups (χ²=5.121, P=0.027) , whereas no significant difference of the recurrence rate (χ²=0.911, P=0.340) . ③ The median dutations of OS between CD123⁺ group and CD123^- group were 20.0 (95%CI 13.1-26.9) months vs 44.0 (95%CI 23.6-47.3) months, respectively (χ²=5.874, P=0.015) ; The median durations of DFS were 7.8 (95%CI 1.4-14.1) months vs 18.6 (95%CI 0-39.7) months, respectively, no differences were observed between the two groups (χ²=2.939, P=0.086) . ④ CD123 retained an adverse prognosis value on DFS and OS within the intermediate group and patients ≤ 50 years older. Conclusions CD123 widely expressed in AML patients, which was an independent risk factor for CR1 and OS, which implicating its important role in evaluating the induction chemotherapy response and prognosis of AML.