Abstract: Because topographical work serves as a tool for national rule and as evidence of national sovereignty, the Qing court treated them with the utmost importance. In the eighteenth century, Kangxi, Yongzheng, and Qianlong, three diligent and conscientious enperors, personally directed and planned empire-wide topographical surveys. During the process of surveying and charting China, Western missionaries proved to be of great benefit to this effort. They contributed Western knowledge of astronomy and geography, along with the most advanced survey techniques, and, in close cooperation with officials of the Qing court, accomplished the formidable task of surveying the total Land area of the empire. This was not only a historic undertaking, but also an outstanding contribution to the development of world cartography.