Childhood acute lymphoblastic leukemia can be divided into standard and high risk according to clinical manifestations, cellular morphological features, immunological and cytogenetic manifestations. According to the experience of several centers, the chances of long-term survival of childhood ALL have reached 80% or even cured by active treatment. To achieve this ideal goal, it is necessary to use the appropriate intense regimens according to the different risk levels of childhood ALL and follow the principle of early and continuous intense chemotherapy. The different risk levels of childhood ALL, using the appropriate intense regimens, and following the principle of early sequential intense chemotherapy. Measures for long-term disease-free survival in childhood ALL . Chemotherapy is still a major effective treatment from the current studies in several treatment centers worldwide for leukemia. Chemotherapy for childhood ALL includes: 1. induction of remission therapy; 2. consolidation therapy; 3. treatment of extramedullary leukemia; 4. early intensive therapy; 5. maintenance therapy.