The national-birth myth in Korean Peninsula has not been possessed separately as the myth, but has been possessed as a part of the history by its becoming the history. Since it has been recognized as a part of the history, in Korean Peninsula, the desires of both the leadership of society and the pundit stratum were strongly projected to the national-birth myth, and as it has quickly become anti-religion, it could freely consume the discussion regarding to the myth at the various viewpoints. In the latter part of Josun Dynasty, the discussion about the national-birth myth of the Sungho School was also no exception in such respect. Though they have ever pursued an empirical study, they accepted the Chinese authentic theory as it is, and reflected it to their history research, therefore through it they watched the ancient history of Korean Peninsula at the distinctive viewpoint. By separating its descent origin from the cultural source, they newly acknowledged the value of Korean Peninsula`s ancient history that had been disparaged, pushed back by Gija Josun, and especially they became to evaluate the substance of Dangun Josun as equal level as Gija Josun. However, on their own situation, the historicize national-birth myth which has been tightly entangled with the ancient history of Korean Peninsula, was not harmonize with the ideal of Chinese civilization, so that for affirmation of the ancient history, it was nothing but a false that should be thoroughly contradicted. Since such Sungho School`s recognition on the national-birth myth had passed far over the doubt with regard to the national-birth myth, this was different from the recognition of the beginning period of Josun Dynasty which skeptical response against the Korean Peninsula ancient history, also it was quite different from the Huh Mok`s perception which accepted both the Korean Peninsula ancient history and the national-birth myth, also Lee Jong Hui`s recognition that acknowledges the certain worth of its own of the myth too, subject to separation the ancient history from the national-birth myth. As those of Sungho School recognized the national-birth myth in such way, they have ever kept the unified flow attitude, deny and disparage neither Dangun Josun nor Gija Josun, therefore they became able to explain the legitimacy that had been connected even to Josun from Chinese Joo Dynasty passing through Gojosun(Ancient Josun). Likewise, due to such reason, it could assert that Josun is not a simple barbarian, but the nation which was inherited Chinese cultural authenticity from the Joo Dynasty. Conforming to such way, the Sungho School could be possible to draw Josun`s figure as an innovated nation of the new Chinese civilization based on Korean Peninsula, by breaking away from the attachment to the Central Districts, also the unscientific reality cognition which were imprudently made without any standard at that time.