Outbreaks from September 1999 to July 2000 of blackleg in 4 milking and fatting cattle farms in the vicinity of Munkyong(northwestern part of Gyeongbuk province) were investigated biochemical characteristics of isolates and were surveyed epidemiological works during the period of 2 months from August to September 2000. Clostridium chauvoei, the etiological agent of blackleg is a serious pathogen of cattle and sheep causing fever, depression and lameness with high mortality in growing phase of 6 to 18 months old mainly beef cattle. Biochemical and cultural properties of 4 isolated Cl chauvoei were identical to those of reported results and isolates were susceptible to ampicillin, bacitracin, chlorarnphenicol, cephalothin, ciprofloxacin, erythromycin, norfloxacin, penicillin, and tetracycline, while they were resistant to amikacin, colistin, gentamicin, kanamycin, neomycin, streptomycin and trimethoprim-sulfamethoxazole. In the results of epidemiological survey, outbreak farms that concentrated region of milking or fatting cattle in each sites were so close contact within a radius of about 1km that they are separated only by wire fence or shrub harrier and flies, rodents, wild cats and birds could have the chance to move around between those farms. The origin of the outbreak blackleg were uncertain, but the transmission between farms were mainly through the movement of farm personnel, vehicles which were struck the feces or manures from farm and other mechanical factors such as flies, rodents and birds furthermore occurred 4 farms were not vaccinated. In conclusion, a periodic disinfection, vaccination and quarantine prevention are ideal methods of damage reduction by blackleg.