Objective: To study the expression of miRNA-181a in acute myeloid leukemia (AML) patients with normal karyotype to probe its prognosis significance. Methods: The expression level of miRNA-181a in bone marrow mononuclear cells of 120 de novo AML patients with normal karyotype was detected by real time fluorescence quantitative PCR. The direct sequencing method was used to detect IDH1, IDH2, NPM1, FLT3-ITD, DNMT3A and CEBPα mutations in CN-AML patients after PCR. The relationship between miRNA-181a expression and gene mutation, the clinical parameters and prognosis were analyzed. Results: The rates of overall surviva1 (OS) in high expression and low expression groups were 25.0 months and 15.0 months, respectively (P<0.05) . Relapse free survival (RFS) in high expression and low expression groups were 21.4 months and 11.2 months, respectively (P<0.05) . Significantly higher level hemoglobin, complete remission rate and proportion of wild type NPM1 expression in the high expression of miRNA-181a group were observed when compared with the lower expression of miRNA-181a group (P<0.05) . Multivariate Cox regression analysis showed miRNA-181a overexpression was an independent prognostic factor for CN-AML (HR=2.219, 95%CI 1.601~2.432, P=0.018) . Conclusion Higher expression of miRNA-181a was a good prognostic factor independent of clinical parameters and high frequency gene mutations, which implicated that the miRNA-181a expression level could be used as an important prognostic indicator of AML patients with normal karyotype.