This article examines the methodological issues arising from the study of science and European imperialism. Drawing upon recent scholarship in a variety of fields, it argues for a combination of the concepts of “cultural borderlands” and “scientific imperialism” in analyzing the formation of science in cultural encounter. It also urges STS scholars to pay more attention to the field sciences. Although the focus of the article is on science and British imperialism in nineteenth-century China, its conclusions address an important aspect of the history of East Asian science, technology, and medicine from the early modern period to the twentieth century.