In this study, antimicrobial resistance of E coli isolated from domestic beef on sale in Busan and Gyeongnam province was investigated from March to October 2007. A total of 600 beef samples were collected for the monitoring of antimicrobial resistance, and 92 (15.3%) strains of E coli were isolated. Antimicrobial resistance test was carried out by agar disc diffusion method with 17 antimicrobials. In general, E coli isolates showed the highest antimicrobial resistance to doxycycline (73.9%), followed by tetracycline (70.7%) andcefazolin (63.0%). Then they showed higher resistance to several antimicrobials like norfloxacin (48.9%). However, They had low antimicrobial resistance to amikacin (4.3%), colistin (1.1%). Of 92 isolates, 82 (89.1%) were resistant to more than 2 antimicrobials. Among 17 antimicrobials examined, tetracyclines were the most resistant, followed by cephalosporins, quinolone. The resistance was seemed to be correlated to amounts of antimicrobial use. In the result of this study, we suggest that there be need to regulate the abuse of antimicrobial on food-producing animals in Korea because the concern on antimicrobial resistant is gradually increased worldwide.