Objective To analyze trends and future projections of lower respiratory infection (LRI) incidence and mortality among children in China from 1990 to 2021, and to compare etiological characteristics across age groups. Methods Epidemiological data for pediatric LRI in China from 1990 to 2021 were obtained from the Global Burden of Disease database. Comparative analyses examined trends and projections for China, the global population, and high socio-demographic index (SDI) regions. The influence of different pathogens on pediatric LRI in China was also assessed. Results From 1990 to 2021, the burden of LRI among children in China was lower than the global average but higher than that in high-SDI regions. Incidence and mortality rates showed a significant downward trend, with the most pronounced decline in children under 5 years of age, while the decline in LRI incidence among those aged 10-14 years was slower than the global level for the same age group. Projections for 2022-2040 indicated continued decreases in incidence and mortality of pediatric LRI in China. Bacterial infections remained the predominant cause of pediatric LRI in China. Marked age-specific differences in pathogen spectra were observed: viral LRI burden was higher in children under 5 years than in those aged 5-14 years, whereas the burden due to atypical pathogens was lower in children under 5 years than in those aged 5-14 years. Conclusions From 1990 to 2021, the overall burden of pediatric LRI in China shows a declining trend and is predicted to continue to decrease. The slower decline in LRI incidence among children aged 10-14 years compared with the global level indicates a weakness in prevention for this age group. Distinct age-specific pathogen profiles suggest the need for age-targeted interventions and continuous surveillance of pathogen spectra.