Transplantation in patients with stage 1 CR: recommended for patients at high risk for: 1. Not achieving hematologic CR at 33 d. 2. Achieving CR but still having microscopic residual disease (MRD) ≥ 10-3 at 12 weeks. 3. With positive MLL gene rearrangement, age < 6 months or WBC > 300×109/L at initiation. 4. With Ph chromosome-positive patients, especially with poor early response to prednisone or MRD not reaching 4 and 12 weeks were negative criteria. Transplantation in patients with ≥ CR2 stage: very early relapsed and early relapsed ALL patients (Annex 1), HSCT is recommended in CR2 stage; all patients with CR3 or higher are indicated for transplantation. Salvage transplantation: for refractory, relapsed unremitting patients, allo-HSCT can be performed on an experimental basis in experienced units.