Cefoperazone/sulbactam is a combination of sulbactam and cefoperazone.It is widely used because of reliable clinical efficacy,safety and its spectrum of activity.This study was to investigate cefoperazone/sulbactam resistance to Gram-negative bacteria isolated in a university hospital in China during the past 7 years.Disk diffusion test was used to study the antimicrobial resistance.The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI).The rates of extended spectrum beta-lactamases (ESBLs) in Klebsiella spp.and Escherichia coli were 51.2％～65.1％and 43.6％～60.1％ during the past 7 years,respectively.Although there was a constant increase in resistance of Gram-negative bacteria in the past 7 years,cefoperazone/sulbactam demonstrated excellent in vitro activity against these pathogens.