The present study was conducted to investigate the biochemical characteristics and anti-biotic resistance of pathogenic Escherichia coli (E. coli) isolated from piglets with diarrhea in Kyongbuk Western Area during the period from February to November 1992. 55 E. coli strains were isolated from 97 piglets with diarrhea and the biochemical and cultural reaction were compared with the classification criteria of Edwards and Ewing. The majority of E. coli were susceptible to amikacln, enrofloxacin and gentamicin. 51 (92.7%) out of 55 drug resistance stains carried R factor (R+) which were transferable to the recipients by conjugation.