An established cell line, KSEK6, derived from swine embryo kidney proved to be a suitable host for the propagation of a hemagglutinating encephalomyelitis virus, strain 67N. Infected cells showed clear cytopathic effect as early as 24 hours incubation at 37 degrees C. Plaques easily visible to the naked eye were also produced under agar overlay medium. The infective titer of 3rd passage level in the cells was in the order of 10(8) PFU per ml. Detecting antibodies against this virus strain in swine sera was considered to be more accurate by neutralization test than by hemagglutination inhibition.