To study the distrubution and drugresistance of Escherichia coli (E. coli) and Klebsiella pneumonia (K. pneumonia) which  produced extendedspectrum betalactamases(ESBLs) in a hospital.MethodsThe doubledisk synergy test was performed to detect ESBLsproducing strains and antimicrobial susceptibility was determined by disk diffusion test in specimens collected from  patients from October， 2007 to September， 2008.Results443 of  766(57.83%) E. coli strains produced ESBLs； 355 of 632 (56.17%) K. pneumonia strains produced ESBLs. Most ESBLsproducing strains were isolated from  sputum (557 strains, 69.80%) and urine (149 strains,18.67%). ESBLsproducing strains were susceptible to imipenem／cilastatin, meropenem and cefoperazone/sulbactam, but resistant to almost all the first to third generation cephalosporins, and had cross resistance among  quinolones and aminoglycosides.ConclusionInfections caused by ESBLsproducing strains are serious, majority are lower respiratory tract infection, the next is urinary tract infection; drugresistance is high, imipenem/cilastatin, meropenem and cefoperazone/sulbactam have high antimicrobial activity on ESBLsproducing strains.