ObjectiveTo investigate the distribution and antimicrobial resistance of pathogens from lower respiratory tract infection in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and provide reference for the rational use of antimicrobial agents in clinic.MethodsSputum culture and antimicrobial susceptibility test were conducted for 200 AECOPD patients who were admitted to a respiratory disease department from January to December 2011, and antimicrobial susceptibility test results were analyzed by WHONET 5.3 software.ResultsOf 200 AECOPD patients, 85 (42.50%) had positive sputum culture, the isolation rate of gramnegative bacilli, grampositive cocci and fungi was 77.65% (66 isolates), 18.82%（16 isolates）and 3.53%(3 isolates) respectively. The top six pathogens were Pseudomonas aeruginosa (36.47%)，Klebsiella pneumoniae (11.76%)，Haemophilus influenzae (10.58%)， Acinetobacter baumannii (9.41%), Streptococcus pneumoniae（9.41%）, and Staphylococcus aureus（8.24%）. Pseudomonas aeruginosa had multiple antimicrobial resistance, the resistant rates to ampicillin,ampicillin/sulbactam, cefazolin, cefotetan,compound sulfamethoxazole, and nitrofurantoin were all 100.00%，to ceftriaxone was 93.55%；the resistant rates of Acinetobacter baumannii to ampicillin, cefazolin,and nitrofurantoin were all ＞75%；the resistant rates of Klebsiella pneumoniae to ampicillin and nitrofurantoin were both ＞60%；the resistant rates of Haemophilus influenzae to ampicillin and compound sulfamethoxazole were both ＞65%. Of 7 Staphylococcus aureus isolates，5 were methicillinresistant.ConclusionThe main pathogens in AECOPD are gramnegative bacilli,and are highly resistant to antimicrobials. Sensitive antimicrobials for gramnegative bacilli should be selected for the treatment, infection with antimicrobial resistant Staphylococcus aureus and fungi should be paid enough attention.