Eighteen strains of Clostpidium perfringens were isolated from the piglets with hemorrhagic enteritis. The characteristics of the outbreaks, clinical signs and lesions were examined. The biochemical properties, type of toxins and susceptibility to antimicrobial agents against the isolates were investigated. 1. The incidence of diarrhea was appeared in 97(22.4%) of 432 piglets examined. 2. The isolation rate of Cl perfingens from the 97 diarrheal faeces were 18.5%(18 strains) 3. The population of Cl perfingens in feces were ranged $10^{8-9}$cfu/g in 5(32.5%) and $10^{3-7}$cfu/g in 13(67.4%) of 18 samples. 4. The toxin type of the 18 isolates investigated by mouse inoculation test was all type C strains of Cl perfringens. 5. As a results of antimicrobial susceptibility test, 18 isolates were higly susceptible to cephalothin, tetracycline and penicillin.