Objective:To explore the relationship between air pollution and the number of pneumonia hospitalization in a children's hospital in Changsha.Methods:Children who have been in this hospital for the treatment of pneumonia between December 2013 and December 2015 were enrolled in this study.Based on daily meteorological data and air pollution data from December 2013 to December 2015 in Changsha,we constructed a generalized additive model to analyze the relationship between air pollution and the number of pneumonia hospitalization.Results:During the research,the average concentration of PM2.5 and PM10 exceeded the Grade Ⅱ national standards for air quality.The average concentration of SO2 exceeded the Grade Ⅰ national standards.The change of all the 3 main air pollution indexes showed strong statistical relationship with the change of the number of pneumonia hospitalization (P＜0.05),among which,the impact of SO2 ranked number 1,followed by PM2.5 and PM10.Effect of atmospheric pollution on the number of pneumonia boys was basically same as that in the total pneumonia children (P＜0.05).The effect on girls showed no statistical relationship in both models (P＞0.05).Conclusion:The concentrations of SO2'PM2.5 and PM10 are positively correlated with pneumonia hospitalization number of children,and their effect on boys is more obvious than that in the girls.