A total of 588 Escherichia coli isolates(133 from swine and 455 from poultry) were collected from six provinces and one city in China between 2003 and 2005.Antimicrobial susceptibility tests for 588 E.coli isolates were performed using broth microdilution method according to the recommendation of the Clinical and Laboratory Standards Institute(CLSI).The results showed that resistance rates to 12 quinolones were very high,ranging from 34.96% to 96.71% among 588 E.coli isolates.Except amikacin,resistant incidence to eight non-quinolones was rather high,ranging from 22.42% to 94.07%.Multi-drug-resistance was very severe and more than 94% of the 588 isolates exhibited multiple resistance to 3 or more antimicrobial agents.Resistance patterns were similar among E.coli isolates from different regions.However the resistance levels were significantly differed from different regions.