As one of the basic study to devise the selective medium for the isolation and enumeration of Fusobacterium necrophorum, the authors have investigated, on the resistances for the several chemical compounds and antibiotics. Following results were obtained 1) The strains of Fusobacterium necrophorum showed the relatively high resistances to crystal violet and streptomycin. 2) The modified medium including 0. 001% of streptomycin and 0. 05% of crystal violet was available to the selective cultivation of Fusobacterium necrophorum from bovine rumen and the liver abscess. (Received June 30, 1974)