Abstract: OBJECTIVE To observe the clinical distribution and drug resistance of extended-spectrum β-lactamase(ESBLs)-producing Escherichia coli and Klebsiella pneumoniae so as to provide guidance for reasonable clinical use of antibiotics. METHODS From Jan 2013 to Dec 2013, the pathogens were isolated from various submitted specimens that were obtained from hospitalized patients with malignant tumor, then the strains were identified by using the kit offered by BioMérieux, France, the drug susceptibility testing was carried out by means of K-B method, and the statistical analysis was performed with the use of WHONET5.4 software. RESULTS Totally 76 strains of E.coli and 63 strains of K.pneumoniae were isolated from the clinical infective specimens from Jan 2013 to Dec 2013, and 46 strains of ESBLs-producing E.coli and 18 strains of ESBLs-producing K.pneumoniae were detected, with the detection rates of 60.53% and 28.57%, respectively; the pandrug-resistant ESBLs-producing E.coli and K.pneumoniae strains were not found.Totally 23.91% of the ESBLs-producing E.coli strains were isolated from drainage fluid, and 72.22% of the ESBLs-producing K.pneumoniae strains were isolated from sputum specimens.The positive rate of ESBLs-producing E.coli was the highest (41.30%) in the department of surgery, while the positive rate of ESBLs-producing K.pneumoniae was the highest (44.44%) in the department of medicine.The ESBLs-producing E.coli and K.pneumoniae strains were highly susceptible to carbapenems, piperacillin-tazobactam, and amikacin, however, the strains were highly resistant to the rest of commonly used antibiotics. CONCLUSION The ESBLs-producing E.coli and K.pneumoniae are dominant among the Enterobacteriaceae isolates causing nosocomial infections in the patients with malignant tumor, both the isolation rate and drug resistance rate show upward trends.It is necessary for the hospital to strengthen the bacteriological examination and reasonably use antibiotics based on the results of the drug susceptibility testing so as to control the spread and prevalence of the ESBLs-producing strains.