This paper examines the “Western learning” in eighteenth-century Korea as a cultural outcome of the informal network of people established between Qing China and Chosŏn Korea as a by-product of the Korean “tributary” travels to the Qing court. This network, consisting of a diverse group of people such as European Jesuits, Qing officials, Korean literati envoys, and professional interpreters and astronomers from both the Chinese and Korean sides, functioned as the main route for transactions of ideas and artifacts. European science and Christianity were among items brought into Korea through this network. Examining travel documents of eighteenth-century Korea, this paper outlines the composition and functioning of the network, and then examines how they shaped the features of “Western learning” in Korea, particularly its general emphasis upon the “material” aspects of the Western learning.