Abstract: In order to investigate the antibiotic resistance and predominant serotypes of porcine enteropathogenic E.coli， 79 strains of E. coli had been isolated from 21 pig farms in Jinhua. All of them were identified with biochemical tests and abdominal injection to mice for characters of pathogenesis. As a result， 68 strains were proved to be pathogenic. Of all the isolates， 68 strains were tested with resistance to 8 kinds of antibiotics. As a result， the isolated E.coli stralus to amikacin， florfenicol， ceftiofur were the most sensitive; Gentamicin， erythromycin， ring although ciprofloxacin and other antibacterial drugs had some effect， but were largely low\|sensitive or moderately sensitive; to ampicillin， norfloxacin were basic resistance. 68 strains were serotyped， among which 7 kinds of serotypes and the predominant serotypes are O13， O54， O98.

Key words: colibacillosis, pathogenic microbe, serotype identification, drug sensitivity test