I discuss on an established view of smallpox vaccination in Korea, 1876-1910. The view has become a kind of myth since its creation in the first quarter of the twentieth century. The myth has a grandiose story like that: "smallpox was an extremely horrible disease; the traditional medicine was absurd in preventing or curing the disease; many relied on superstitious methods such as a prayer and an exorcism against the disease; introduction of smallpox vaccination, however, changed fundamentally the hopeless situation; eventually smallpox in Korea had been eradicated after the introduction of the vaccination; Ji Seog-Yeong(池錫永), a greater pioneer, played a decisive role in rooting smallpox vaccination in Korea; the credit for eradicating smallpox goes to him." This myth was constructed by Japanese rulers during the Japanese occupation period(1910-45). By emphasizing the great hero, Ji Seog-Yeong, who had studied smallpox vaccination from Japanese. Japanese rulers intended to cover up systematic actions of Korean government, occupied by Japan in 1910, and to awake their contribution to planting smallpox vaccination in Korea. They also want to justify their ruling over Korean by using the example of their contribution to Korean such as smallpox vaccination. The above myth, however, is a story full of exaggerations. With more detailed primary materials, I construct a different story in this article.