Objective To study the distribution and antimicrobial resistance of the bacterial strains isolated from lower respiratory tract in children,to provide evidence for better clinical management.Methods The medical data of children (0-5 years of age) with lower respiratory tract infection were retrospectively reviewed.The children were treated during the period from September 2014 to September 2016.Results Of the 4815 sputum samples collected from the lower respiratory tract of children,1582 (32.86％) had a positive bacterial culture.A total of 1614 strains of pathogens were identified.The most common bacterial pathogen was Haemophilus influenzae (9.66％),followed by Streptococcus pneumoniae (7.12％) and Moraxella catarrhalis (5.15％).The bacterial detection rate varied greatly with season and the age of children (P＜0.01).H.influenzae,M.catarrhalis and S.pneumoniae isolates showed lower resistance rate to cefotaxime,all ＜20.0％.Escherichia coli and Klebsiella pneumoniae isolates showed lower resistance rate to cefotetan,imipenem and piperacillin tazobactam,all ＜ 10％.Less than 20％ of the S.aureus strains were resistant to oxacillin.Conclusions H.influenzae is the most frequently isolated pathogen from lower respiratory tract in children aged 0 to 5 years in Neijiang Sichuan Province,followed by S.pneumoniae and M.catarrhalis.The detection rate of bacterial pathogens varies with season and the age of children.Antimicrobial agents should be selected rationally based on the results of antimicrobial susceptibility testing to reduce the occurrence of antibiotic resistance in clinical pathogens.