Objective To investigate the distribution and constituent of drug‐resistant bacteria of lower respiratory tract in‐fection among different regions (outpatient department ,wards ,RICU) to provide the basis for the clinical reasonable application of antimicrobial agents .Methods The K‐B disc diffusion method and the instrument method (VITEK‐TWO) were adopted and the detection results were interpreted according to the standards of CLSI 2010 .The detection data of 480 drug‐resistant strains isolated from the sputum ,branchoalveolar lavage fluid samples submitted in 3 regions of respiratory outpatients department by bacterial cul‐ture identification and drug susceptibility test were analyzed by using the WHONET5 .6 statistical software .Results The distribu‐tion and constituent of drug‐resistant bacteria of lower respiratory tract infection had obvious difference among 3 different regions . The top 4 of drug resistant bacteria were dominated by Gram‐negative bacteria .The drug resistance rate of Klebsiella pneumoniae in RICU was higher than that in the respiratory outpatients department and wards(P<0 .05) ,the resistance rate in the respiratory outpatients department ,wards and RICU to commonly used antibacterial drugs was similar;the multiple drug resistance of ESBLs‐producing strains was obviously higher than that of non‐ESBLs‐producing strains (P<0 .05) .Pseudomonas aeruginosa maintained the higher antibacterial activity to quinolone ,aminoglucosides ,cefepime ,imipenem ,cefoperazone/sulbactam ,and piperacillin/tazobactam ,but the resistance rate in RICU was significantly higher that in the respiratory outpatient department and wards (P<0 .05);the drug resistance of Acinetobacter baumanii in the respiratory wards and RICU was higher than that in the respiratory out‐patient department ,the resistances to imipenem were 64 .6% and 70 .4% respectively .The resistance of MRSA to rifampin in RICU was higher than that in the respiratory outpatient department and wards(P<0 .05) .Conclusion The distribution constituent and drug‐resistance rates have obvious differences among the respiratory outpatient department ,wards and RICU .Except being familiar with the drug resitant bacterial distribution and drug resistance rate monitoring situation ,clinical doctors should grasp the drug re‐sistance situation of drug resistant bacteria among different areas in various departments of own unit in order to rationally and effec‐tively use antibacterial drugs .