Abstract： Objective To observe the clinical efficacy and adverse reaction of the combination of fiudarabine,cytarabine and granulocytecolony-stimulating factor (G-CSF) (FLAG regime) therapy for refractory and relapsed acute leukemia in children. Methods From 2004 to date, a total of 9 patients with relapsed and refractory acute leukemia patients in our hospital accepted the treatment, in 9 cases 8 cases were AML,1cases were ALL; in 9 cases 5 cases were refractory acute leukemia, 4 cases were recurrent acute leukemia.Results Among the 9 cases,6 cases with 1 cycles of chemotherapy achieved complete remission (CR),CR rate was 66.7 ％ (6/9); partial remission (PR) rate was 22.2 ％ (2/9),total efficiency (CR+PR) was 88.9 ％.In 6 CR patients 2 underwent hematopoietic stem cell transplantation, are disease-free survival; this regimen' s main adverse reactions were infection,bone marrow depression and gastrointestinal reaction.Conclusion The remission rate of FLAG regimen in the treatment of children with refractory and relapsed acute leukemia is relatively high, adverse reactions were tolerable; the FLAG program is a choice for the treatment of children with refractory and relapsed acute leukemia,which provides the opportunity for subsequent hematopoietic stem cell transplantation.