Abstract: ob＜x＞jective To investigate the role of neutrophil to lymphocyte ratio (NLR) as a marker in the diagnosis and prediction of refractory Mycoplasma pneumoniae pneumonia (RMPP) in children. Methods 142 patients with mycoplasma pneumoniae pneumonia (MPP) who were hospitalized in the second Department of Respiration, Xuzhou Children’s Hospital from January 2021 to December 2021 were retrospectively selected as the research subjects and were divided into ordinary MPP group (101 cases) and RMPP group (41 cases). Clinical data, white blood cell (WBC), neutrophil (NUE), platelet (PLT), NLR, C-reactive protein (CRP) and procalcitonin (PCT) were compared between the two groups. The receiver operating characteristic curve (ROC) was used to determine the cut-off values of three biomarkers with statistical significance. Logistic regression analysis was performed to identify independent predictors of RMPP. Results There were no statistically significant differences in age, fever, NEU, NLR and CRP between the RPMM group and the MPP group (all P<0. 01). The area under the ROC (AUC) of NLR in diagnosing RMPP patients was 0.854, and the specificity and sensitivity were 79.2% and 87.8%, respectively. According to binary Logistic regression analysis, NRL, NUE and CRP were independent risk factors for RMPP (all P<0. 01), and the relative risk range was NLR>CRP>NUE. Conclusion NRL can be used as a diagnostic and predictive index of RMPP