Abstract：To determine the effect of sulbactam and EDTA on the antibacterial activity of antimicrobial drugs in vitro, The MICs of 10 antimicrobial agents alone and their respective combinations with sulbactam, EDTA and sulbactam+EDTA against ESBLs–producing E.coli, were determined by using broth microdilution method. The results showed that sulbactam and EDTA can enhence the antibacterial activity of parts of antimicrobial agents, the resistant rate of ESBIs–producing isolates to third generation cephalosporin ceftiofur, cefotaxime was higher than 80% and the resistant rates to fluoroquinolones, doxycycline,florfenicol,am-ikacin and fosfomycin were up to 100%. All the ESBIs-producing isolates were sensitive to cefepime. The resistant rate to third generation cephalosporin cefotaxime, florfenicol, amikacin and fosfomycin combinations with sulbact-om,were lower than that to antibacterial drugs alone, is 0, 88.9%, 88.9%, 0 respectively. The resistant rate to gatifloxacin, doxycycline, florfenicol,amikacin and Fosfomycin combinations with EDTA, were lower than that to antibacterial drugs alone, is 30%, 11.1%, 22.2%, 11.1%, 0 respectively. The resistant rates of most strains to amikacin, fosfomycin, florfenicol and ceftiofur combinations with sulbactom+EDTA were more lower than those to combinations only either sulbactam or EDTA and were all 0.