Objective:To explore the predictive effect of European treatment and outcome study long term survival (ELTS) score on survival outcomes in chronic myeloid leukemia of chronic phase (CML-CP) children.Methods:A single-center retrospective cohort study was conducted. Clinical data of 216 children with CML-CP in Peking University People′s Hospital from January 2010 to December 2023 were analyzed. Children were divided into low, intermediate and high-risk groups according to ELTS score. The survival outcomes and prognostic factors were analyzed. Kaplan-Meier method and Log-Rank test were used for survival analysis.Cox regression model was applied for analysis of prognostic factors.Results:Among the 216 children with CML-CP, there were 122 males and 94 females, with the diagnosis age of 11.0 (8.0, 14.7) years. The follow-up time was 77 (57, 99) months. According to ELTS score, 145, 52, and 19 children were classified as low, intermediate and high-risk group. For the low-risk and intermediate/high-risk groups, the 6-year failure-free survival (FFS) rates were (83.0±3.1)% and (64.6±5.7)%, the 6-year progression-free survival (PFS) rates were (91.4±2.3)% and (78.7±4.8)%, and the 6-year event-free survival (EFS) rates were (80.8±3.3)% and (64.2±5.7)%, with statistically significant difference ( χ2=9.45, 7.16, 7.40, P=0.002, 0.007, 0.007), respectively.The 6-year overall survival (OS) rates were (98.5±1.0)% and (95.6±2.4)%, without statistically significant difference ( χ2=0.35, P=0.550). Multivariate analysis showed that ELTS score was an independent prognostic factor or tendency for FFS ( HR=1.97, 95% CI 1.11-3.49), PFS ( HR=2.95, 95% CI 1.18-7.39), and no independent prognostic factor for EFS and OS were found. Conclusions:ELTS score at diagnosis can help stratify the risk of children with CML-CP. The children in intermediate/high-risk group are more likely to have treatment failure, disease progression than those in low-risk group, but the predictive ability of ELTS score for OS is limited.