Abstract: OBJECTIVE To investigate the drug resistance phenotypes and genes in multidrug-resistant Klebsiella pneumoniae causing intestinal and respiratory tract infections in patients of intensive care unit (ICU) and explore the correlation between pulmonary infections in the ICU patients and intestinal bacteria so as to provide guidance for control of the respiratory tract infections in the ICU patients. METHODS Totally 50 stool or rectal swab specimens and 50 sputum specimens were collected from 50 patients with pulmonary infections who were treated in the hospital from Jan 2014 to Dec 2014, then the submitted specimens were cultured by using ESBLs chromogenic agar and blood agar medium, the multidrug-resistant strains were screened out, the bacterial identification was carried out by means of VITEK-2 Compact automatic bacteria analyzer, the drug susceptibility testing was performed to compare the drug resistance of the multidrug-resistant strains, the common β-lactamase-resistant genes were detected by using PCR, and the homology was analyzed with the use of ERIC-PCR. RESULTS A total of 50 strains of K.pneumoniae were isolated from the rectal swap specimens, of which 44.0% (22 strains) were ESBLs-producing K.pneumoniae, and 12.0% (6 strains) were pandrug-resistant K.pneumoniae. Totally 38 strains of K.pneumoniae were isolated from the respiratory tract specimens, of which 55.3% (21 strains) were ESBLs-producing K.pneumoniae, and 10.5% (4 strains) were pandrug-resistant K.pneumoniae. The carrier rates of the CTX-M, TEM, and SHV genes in the K.pneumoniae isolated from the rectal swab specimens were 48.0%, 44.0%, and 18.0%, respectively; the carrier rates of the CTX-M, TEM, and SHV genes in the K.pneumoniae isolated from the respiratory tract specimens were 36.8%, 44.7%, and 21.1%, respectively; there was no significant difference. The homology analysis showed that the K.pneumoniae strains isolated from the intestinal and respiratory tract specimens were highly homologous. CONCLUSION The K.pneumoniae strains isolated from the intestinal and respiratory tract specimens in the ICU patients are highly homologous, and there is a higher consistency in the multidrug-resistant genes between them.