Clostridium (C.) novyi is a gram-positive,obligate an aerobic,and endospore-forming bacteria. C.novyi is classified into 4 strains (A to D type) by the exotoxins, and the lethal and necrotizing alpha toxinis considered to be the principle toxin of the type B strain in pigs. This toxin causes necrosis by increasing permeability of the cell barrier, and disrupting intercellular junctions. So, C.novyi type B commonly causes infectious necrotic hepatitis, so called black diseases, and it has been observed in sheep and other animals. The infected liver uniformly infiltrated with many gas bubbles, so the liver presents a spongy appearance on the cut surface. Although the C.novyi infections are unusual in pigs, cases of sudden death in sows have been reported in Europe. This experiment detected the production of specific antibodies of C.novyi type B toxoid using ELISA in swine sera.