Background:Monitoring the dynamic changes of measurable residual disease (MRD) in patients with acute myeloid leukemia (AML) to predict prognosis and guide treatment has become a consensus among hematologists.The NPM1 mutation has emerged as a crucial method for MRD monitoring. Digital droplet PCR (ddPCR), as a third- generation PCR technique, offers greater objectivity through absolute quantification and is more cost-effective than NGS, thus assuming a more prominent role in MRD monitoring. Therefore, it is necessary to investigate the utility of detecting mutated gene MRD by ddPCR for non- allo-HSCT AML patients with regard to their prognosis and whether it can serve as a complementary method for MFC based MRD monitoring.