The efficiency of dendritic cell-activated and cytokine-induced killer cell(DC-CIK) therapy on children with acute myeloid leukemia(AML) after chemotherapy was investigated. Mononuclear cells were collected from children achieving complete remission after chemotherapy,cultured in vitro and transfused back into the same patient. Interleukin-2(IL-2) was injected subcutaneously every other day 10 times at the dose of 1×106 units. Peripheral blood lymphocyte subsets and minimal residual disease(MRD) were detected by flow cytometry. Function of bone marrow was monitored by methods of morphology,immunology,cytogenetics and molecular biology. The side effects were also observed during the treatment. The average follow-up period for all the 22 patients was 71 months and relapse occurred in two AML patients(9.1%). The percentage of CD3+/CD8+ cells in peripheral blood of 15 patients at the 3rd month after DC-CIK treatment(36.73%±12.51%) was dramatically higher than that before treatment(29.20%±8.34%,P<0.05). The MRD rate was >0.1% in 5 patients before the treatment,and became lower than 0.1% 3 months after the treatment. During the transfusion of DC-CIK,side effects including fever,chills and hives appeared in 7 out of 22(31.82%) cases but disappeared quickly after symptomatic treatments. There were no changes in electrocardiography and liver-renal functions after the treatment. MRD in children with AML can be eliminated by DC-CIK therapy which is safe and has fewer side effects. The efficiency of dendritic cell-activated and cytokine-induced killer cell (DC-CIK) therapy on children with acute myeloid leukemia (AML) after chemotherapy was investigated. Mononuclear cells were collected from children achieving complete remission after chemotherapy, cultured in vitro and transfused Interleukin-2 (IL-2) was injected subcutaneously every other day 10 times at the dose of 1 × 106 units. Peripheral blood lymphocyte subsets and minimal residual disease (MRD) were detected by flow cytometry. Function of The bone marrow was monitored by methods of morphology, immunology, cytogenetics and molecular biology. The average follow-up period for all the 22 patients was 71 months and relapse in two AML patients (9.1% The percentage of CD3 + / CD8 + cells in peripheral blood of 15 patients at the 3rd month after DC-CIK treatment (36.73% ± 12.51%) was clarity higher than that before treatment (29.20% ± 8.34%, P <0.05). The MRD rate was> 0.1% in 5 patients before the treatment, and was lower than 0.1% 3 months after the treatment. During the transfusion of DC-CIK, side effects including fever, chills and There were no changes in electrocardiography and liver-renal functions after the treatment. MRD in children with AML can be eliminated by DC-CIK therapy which is safe and has fewer side effects.