Abstract:The Ditan was built in 1530 and extended during the reign of Emperor Qianlong of the Qing Dynasty. It is the place of Ming and Qing emperors sacrificed to the Earth. The emperor's sacrifice room is one of the important buildings of Ditan. The emperor's sacrifice room Inner eaves color patterns is the early practice of "Dragon patterns", which belongs to the mid Qing dynasty color patterns style, and the late Qing Dynasty Dragon patterns have a significant difference. It's an important historical site for studying Dragon patterns .