〔Abstract〕 Abstract Objective To investigate the diagnostic value of plasma calprotectin in refractory mycoplasma pneu- moniae pneumonia. Methods A multicenter , prospective cohort study was conducted , enrolling 228 children with mycoplasma pneumoniae pneumonia ( MPP) . Among these , 177 cases were diagnosed with general mycoplasma pneumoniae pneumonia (GMPP) , while the remaining 51 cases were refractory mycoplasma pneumoniae pneumonia (RMPP) . Plasma was collected at the time of admission of the children in both groups , and calprotectin levels were measured . A one-way difference analysis was performed on the blood test indexes of the children in the two groups , and the difference variables with P < 0. 05 between the two groups were included in a multifactorial logistic regression to analyze the risk factors for the progression of GMPP to RMPP. The differential diagnostic value of plas- ma calprotectin for GMPP and RMPP was analyzed by the receiver operating characteristic (ROC) curves . Results Univariate analysis showed that plasma calprotectin levels were significantly higher in the RMPP group than those in the GMPP group , and the difference was statistically significant (P < 0. 05) . Logistic regression analysis showed that plasma calprotectin was an independent risk factor for RMPP (OR = 1 . 323 , P < 0. 001) , ROC curve analysis showed that plasma calprotectin had a higher diagnostic value for the differential diagnosis of GMPP and RMPP (AUC = 0. 839) , and its combination with C-reactive protein and albumin could significantly improve the diagnos- tic efficiency . Conclusion Plasma calprotectin has good clinical value for the diagnosis of RMPP.