Mycoplasma pneumoniae is one of the common pathogens of pulmonary infection in children, and humans are the only host.Mycoplasma pneumoniae pneumonia is a common community-acquired pneumonia in school-age children, accounting for 10%-40% of CAP in hospitalized children.In the early stage, due to macrolide resistance and a series of complex mechanisms, the incidence of refractory Mycoplasma pneumoniae pneumonia continued to increase, often leading to poor prognosis and sequelae such as atelectasis, pulmonary necrosis, bronchiectasis, and bronchiolitis obliterans. .Some studies have found that the microbiota changes significantly during lower respiratory tract infection, which is closely related to the prognosis or course of pneumonia.This study conducted mNGS pathogenic examination on bronchoalveolar lavage fluid from children diagnosed with RMPP or non-refractory Mycoplasma pneumoniae pneumonia (NRMPP), and analyzed the relationship between the lower respiratory tract microbiota and RMPP. The relevant research results were published in Translational Pediatrics.