This study has begins from hypothesis that Jumong mythology will discover the protype of imagination the people who have handed over mythology have commonly. Especially, this thesis named the imagination concerned with materials and structure narrative imagination presuming that imagination of the community will be reflected in the way materials and structure of story is constructed. This thesis considers Jumong mythology to be heroic mythology, and hero to be independent subject. This thesis could confirm that, in the mythology, the special narrative structure is concerned with making a hero like other narratives. In this case of hero mythology, the narrative structure of disconnection-introduction operates significantly, and in Jumong mythology, there were large parts in which disconnection with parents and hometown were made clear. In addition to it, this thesis could consider that, in this mythology, narrative imagination of Jumong mythology was operated in the way it was disconnected with parents and hometown though they operated as materials in this mythology. Disconnection with parents was concerned with the issue of denial of biological relation, and this denial of biological relationship was linked with escaping from hometown.So it became a condition of independent subject. This mythology presented pointing to imaginative parents as a way to deny the biological parents. In this progress, this mythology discovered illusion to compensate shortage. It seemed that illusion was a basic operation to disorganization of the first family relation. If the first dependent relation between object and subject comprising the relation with the family is described as a internal nature, it can be said that internal nature is denied in this mythology characteristically. Denial of internal nature is to be an instrument, and it is possible when the problem that subject secures independence denies the object, that is, it considers natural conditions to be an instrument.