Objective:The epidemiological characteristics and drug susceptibility changes of Pseudomonas aeruginosa(PA) infection in the respiratory tract of children in suzhou were analyzed in order to provide guidance and suggestions for the rational use of antibiotics in this region. Methods:Bacterial culture results of nasopharyngeal secretions from 21 176 children admitted to the Department of Respiratory, Children′s Hospital Affiliated to Soochow University for respiratory tract infections from January 2008 to December 2017 were collected.According to age, season, underlying disease conditions and the presence of intensive care units (ICU) during the hospitalization, these children were divided into different groups.The epidemic characteristics of PA infection were monitored, and changes in PA drug sensitivity were dynamically observed.Results:Among 21 176 nasopharyngeal secretions from children with respiratory tract infection, 191 cultures were detected with PA, and showing a positive detection rate of 0.90% (191/21 176 cases). The annual detection rate was different.The highest detection rate was 2.24% (50/2 234 cases) in 2009 and the lowest was 0.41% (9/2 207 cases) in 2014.The detection rate of PA in children with in >6 months to 1-year-old group was the highest (1.52%, 53/3 497 cases), and the lowest was 0.57%(11/1 934 cases) in the >5-year-old group.The detection rates of PA in spring, summer, autumn, and winter were 1.11% (60/5 420 cases), 1.21% (61/5 046 cases), 0.81% (46/5 670 cases), and 0.48% (24/5 040 cases), respectively.The difference of PA detection rates between summer (the highest rate) and the winter (the lowest rate) was statistically significant ( χ2=18.611, P<0.001). Among the 21 176 children, 18.89% (4 000/21 176 cases) had basic diseases, and the PA detection rate in such kind of patients was 1.28% (51/4 000 cases), which was higher than that in patients without basic diseases (0.82%, 140/17 176 cases). The PA detection rate in the ICU group was 4.41% (15/340 cases), which was significantly higher than that in the general group (0.84%, 176/20 836 cases) ( χ2=7.678, 47.623, all P<0.05). There were no strains susceptible to Ampicillin, Ampicillin/Sulbactam and compound Sulfamethoxazole, and no strains susceptible to Ceftriaxone from 2010 to 2017.The susceptibility rate to Imipenem was low from 2012 to 2015, and the lowest was only 66.7% in 2014.The sensitivity rate to Aztreonam fluctuated significantly from year to year.Strains were all highly sensitive to Piperacillin, Piperacillin Tazobactam, Ciprofloxacin, Levofloxacin, Gentamicin, and Tobramycin. Conclusions:PA infection is prone to occur in young children with basic diseases and relatively severe illness.Summer is a high-incidence season.PA is generally highly resistant to commonly used antibiotics.