Cattle was inoculated with the Fusan strain cattle type of the rinderpest virus that was isolated in Busan (Korea) in the 1920's, and the pathogenicity was examined. The change of temperature, the clinical symptom and pathologic finding of the experimental infection were similar to ones in the 1940's, and it was confirmed that the rinderpest virus has kept the same pathogenicity in those days. A realtime PCR was developed to examine the amount of excretion of the virus from the feces and the nasal discharge of the cattle. The virus was detected in both after 66 hours and the most amount of total excretion was after 120 hours after the infection. As for each amount of excretion, the amount in the feces was seven, twenty four and sixty five times in 114, 120 and 126 hours after the infection respectively, more than those in the nasal discharge by the realtime PCR. The results suggested that the excretion from the feces was important in the spread of the rinderpest virus