A total of 35 strains of Shigella sonnei, 21 strains isolated in South Korea from 2000 to 2001 and 14 strains isolated in Japan from 2001 and 2002 were analyzed for antimicrobial susceptibility, plasmid profile and molecular epidemiology. Using polymerase chain reaction (PCR) method, the strains were tested for the presence of virulence genes. And then reversed passive latex agglutination (RPLA) test was used to determine if the strain was Shiga-toxin producing. Their random amplified polymorphic DNA (RAPD) patterns were examined. Pulsed-field gel electrophoresis (PFGE) patterns were also analyzed. Most strains showed multiple resistance to more than four antimicrobial agents, i.e., tetracycline, erythromycin, streptomycin and vancomycin. All South Korea strains were susceptible to chloramphenicol and gentamicin, while all Japan strains were susceptible to kanamycin and cefoperazone. The antibiogram could be classified into 6 groups. By PCR, ipaH gene was detected from all strains, but set1A and set1B genes were not. Sen and ial genes were detected from 19 strains (54.3%). Especially, stx gene was positive in 11 of the 35 strains by PCR method but not confirmed by RPLA method. The strains were differentiated into 12 groups by plasmid profile and 6 arbitrary groups (a to f) by RAPD analysis. The isolates could be grouped into 5 (A to E) PFGE patterns including 3 subgroups A-1, A-2 and A-3. Type A was the major type (82.9 %).