1. When newly diagnosed pediatric and young adult CML patients have a matched sibling donor. If other donors with better matches are available, transplantation can also be performed with full parental knowledge and understanding of the pros and cons of transplantation. 2. Patients in the chronic phase who have a Sokal score {critical and EBMT risk score ≤2 and have an HLA compatible donor may choose transplantation as first-line treatment. 3. For patients in the chronic phase who have failed imatinib therapy, transplantation can be considered according to the patient’s age and wishes. 4. allo-HSCT is preferred for patients with T315I mutation in the BCR-ABL gene during imatinib treatment or at any time. 5. allo-HSCT is available for all patients with poor response, failure or intolerance to second-generation tyrosine kinase inhibitor (TKI) therapy. allo-HSCT is recommended for patients in the accelerated or acute phase, and is preferred before transplantation TKI smut therapy.