Six strains of Bacteroides fragilis group were isolated from clinical specimens, and these isolates were classified by the resistance to bile and kanamycin, and by catalase and indole reaction. Of 6 strains, 4 strains were belonged to B. fragilis and 2 were B. uniformis. Among 6 strains, only 2 of B. fragilis harbored plasmids. But these plasmid showed no correlation with phenotypic expression. There were some differences in susceptibility to 23 ${eta}$-lactam antibiotics, also, marked susceptibility differences were found between 2 species, so these results may be contributed to the treatment of infection due to this micro-organism and the identification of these species.