The word "Korea" is used to refer to "ancient Korea" in the Korean history book "Heritage of the Three Kingdoms", that is, Tan Jun Korea (a myth invented in the 2nd century/kloc-0), "Jizi Korea" and "Wei Man Korea". In China's history books from the Zhou Dynasty to the Han Dynasty, "Korea" only refers to the northern part of the Korean Peninsula, which is the local government under the counties of China, while the southern part of the Korean Peninsula is called "three Koreas" (namely Chen Han, Mahan and Han Ge). In BC 194, Wei Yanman overthrew the quasi-Koryo king of ji zi, whose country name was still called "Koryo", which was called Wei Mang Koryo in history. In the second year of Yuanfeng in the Western Han Dynasty (BC 109), Emperor Wu of the Han Dynasty invaded Korea eastward and established four counties. Since then, the word "Korea" has long since disappeared from China's classics. It was not until the late14th century that Zhu Yuanzhang, the founding emperor of the Ming Dynasty, chose North Korea as the country name. South Korean officials adopted modern myths and legends as the beginning of Korean history. But this does not deny that Confucius once mentioned Korea, the country of oriental scholars. But in fact, there is no connection between the two, just because Zhu Yuanzhang gave Li Chengqi the name of North Korea, which is not a nation and has no continuity (the difference is 2400 years! )。