The aim was to study minimal residual disease (MRD) in blood and bone marrow after complete remission of patients with acute myeloid leukemia (AML) and explore the role of MRD in detecting relapse of acute myeloid leukemia. The blood and bone marrow samples from 33 AML patients who had been in complete remission were determined for residual leukemic cells (RLC) with flow cytometry. The results showed that RLC in AML group of complete remission was higher than that of normal group both in blood by (4.7518 +/- 4.1537)% vs (0.4835 +/- 0.2005)% and bone marrow by (17.9082 +/- 20.4819)% vs (0.7285 +/- 0.2209)%, while the RLC in relapsed group was higher than that in non-relapsed group both in blood by (2.233 +/- 1.5923)% vs (10.2369 +/- 9.4714)% and bone marrow by (4.779 +/- 3.0336)% vs (38.0685 +/- 19.4295)%. In conclusion, early detection of leukemic residual cells with flow cytometry contributes to treatment of relapse in time.