Zuo Yun You Yu is obtained through the change of time. It is found in the map of Shanxi Province that there are two counties in the north, which are located in the south of the Great Wall, namely Zuoyun County and Youyu County. Among them, Zuo Yun belongs to Datong City in the east and You Yu belongs to Shuozhou City in the west. The names Zuo Yun and You Yu were not derived from writing couplets, but were finally obtained after some complicated and long-term changes. Zuoyun County is located in Saibei Plateau, adjacent to Datong in the east, Youyu in the west, Shuozhou in the south and Hohhot in the north, with a total area of 1.294 square kilometers. It has a long history. Humans lived here more than 100,000 years ago. In the Spring and Autumn Period, it was the pasture of the northern cypress people, in the Warring States Period, it was Wuzhou, and in the Han Dynasty, it was changed to Hengzhou. The Yuan Dynasty was a territory of Datong, and Hongwu was in the fourth year of Ming Dynasty (66 years).