Objective To understand infection and drug resistance of bacteria in respiratory tract of senile inpa-tients with multiple acute exacerbation in chronic obstructive pulmonary disease(COPD). Methods An analysis of the common culture of sputum specimens and drug sensitive experiment in 399 senile inpatients with acute exacer-bation of chronic obstructive pulmonary disease (AECOPD) who were hospitalized more than or equal to two times. Results 172 strains of bacteria were isolated, and gram negative bacilli accounted for 86. 05% and the top three were A. baumanii, P. aeruginosa, K. pneumoniae. Drug sensitive experiment showed that extensively drug-resist-ant (XDR) rate of A. baumanii decreased and XDR rate of P. aeruginosa and K. pneumoniae increased in 2014 compared with that in 2013, but no significant difference was detected. A. baumanii was all resistant to ampicillin, cefazolin and cefotaxime. P. aeruginosa was seriously resistant to more than one drug, and the resistance to mero-pene increased significantly in 2014. The sensitivity of K. pneumoniae to more than one drug decreased markedly in 2014. Conclusion Gram negative bacilli are the main bacteria in respiratory tract of senile patients with AECO-PD, hospitalized more than or equal to two times, and antibiotic resistance is serious. Understanding the distribu-tion and drug resistance of common bacteria may be helpful to guide the rational use of antibiotics before the drug sensitivity test.