Soil samples from five different areas in Korea were collected during 2001/02 and examined for presence of the genus Clostridium. Direct immuno-fluorescent assay (IFA) examination showed that Clostridium septicum, Cl. novyi and Cl. chauvoei were detected in the soil of specific areas in Korea. Sixteen species of Clostridium were isolated and cultivated from the soil samples. Cl. peifringens was detected in all sampling locations, while the other species were not. The in vitro activity of 14 antibiotic agents was determined against 421 clostridia isolated from the soil contaminated with animal feces in Korea. Trovafloxacin was effective against all isolates of the genus Clostridium except one isolate of Cl. subterminale, two of Cl. tetani, and three of Cl novyi with $MIC_{50}$ $8- 16mu$g $ml^{-1}$. Thirteen species of Clostridium were resistant to vancomycin except for Cl. perfringens, Cl. sporogenes, and Cl. subterminale. Imipenem and trovafloxacin showed high antimicrobial activities (>95%) against all strains in the clostridia investigated. Therefore, antibiotic agents such as imipenem and trovafloxacin are the most suitable agents for polymicrobial infection as broad-spectrum monotherapy.