The founding t ime of the "Nine f ront iers" of the Great Wal l was inconclusive so far. This issue is an important basement for the further research of the Ming Great Wall and the military fortress along the Great Wall. People nowadays have three versions on the founded time of Ji-town, namely in Yongle Period, Xuande Period, and Jiajing Period. The records are different in the history books and literature recordation, even on the founding sign of Nine-frontiers. The historical information about the founded time of Ji-town mainly recorded in the history books and relative inscriptions, such as Ming Shi Lu, Huangming Jiubian Kao,Si-zhen Sanguan Zhi, Jiubian Tushuo, Lulong Sailue. This paper makes the texture research on the above issues by comparative analysis.