〔Abstract〕 Objective To investigate the value of serum matrix metalloproteinase-9 (MMP-9), E-selectin, serum amyloid A (SAA) and C-reactive protein (CRP) in identifying the type of pediatric pneumonia infection. Methods From December 2020 to December 2022, 96 children with pneumonia diagnosed and treated in Gansu Provincial Maternal and Child Health Care Hospital were selected as the study subjects, among the 96 children, the pathogen detection results were viral infection in 66 cases (virus group), and there were 30 children with bacterial infection (bacterial group). And the serum MMP-9, E-selectin, SAA, and CRP levels of all children were detected to compare the differences of each index in children with different types of infections, and the diagnostic value of each index was analyzed by using the receiver operating characteristic curve (ROC). Results Compared with the bacterial group, the levels of serum MMP-9, E-selectin, SAA and CRP in the viral group were significantly higher, with statistical significance (P < 0.05). ROC curve results showed that the area under the curve (AUC) of serum MMP-9, E-selectin, SAA and CRP were 0.727, 0.715, 0.678 and 0.669, respectively. Conclusion The types of pediatric pneumonia infections are mainly viral infections, and viral infections in children with pneumonia are often accompanied by elevated levels of serum MMP-9, E-selectin, SAA, and CRP. Serum MMP-9, E-selectin, SAA, and CRP all have a high discriminatory value for pediatric pneumonia infection types.