Focusing on the craft aspect of population research—the generally unremarked fact that behind our well-turned-out publications lie particular, historically situated humans using craft-type techniques—this essay traces the history of the making of population knowledge about China by the author over some twenty-five years. At least in this case, population research has taken the form not of a stable subdiscipline, but of a loose, flexible, opportunistic assemblage—of concerns, logics, techniques, methods, and ethics—that has been guided by some of the big questions posed by China's post-Mao global rise. It suggests that, unlike disciplines and inter-disciplines, population studies is a post-disciplinary assemblage whose contents and boundaries are flexible, varying with the practitioner and the research question being explored. Recounting more individual histories of population knowledge-making would help us see the strong shaping role of historical contexts and personal values in the crafting of population thought. Such insights would help us recognize the diverse pathways by which population knowledge is formed and the different purposes for which it is pursued.