Mutations in DNA methyltransferase 3A (DNMT3A) gene were recently demonstrated in acute myeloid leukemia(AML). Approximately 20% patients with AML carry DNMT3A gene mutations and was associated with a poor clinical outcome. but its clinical implications in Chinese AML patients are largely unknown. We analyzed 101 adult AML patients in china and found 14 patients (13.9%) harboring this mutation. 9 patient with M5, 2 patients with M1, 2patient with M2 and 1 patient with M3. We identified 11 missense mutation,2 nonsense and 30 bp deletion encompassing DNMT3A. The most common of them was predicted to affect 882Arg(in 4 patients). Double mutations were detected in two cases.10 of 33(43.5%). DNMT3A mutations occurred more frequently in older (age > 50y,p < 0.05) and the outcome is too badly for these patients. We concluded that DNMT3A mutations are highly recurrent in AML and is associated with distinct clinical and biologic characteristics and seems to be a useful as a prognostic marker.