This article revisits the question of the impact of the Green Revolution in the rice-farming region of South China, combining historical and anthropological approaches to technological transformation. The article describes the Chinese “traditional” practice of small-scale wet-rice farming as a technological system and provides detailed microhistorical data on the various kinds of social and material transformations operated on this “traditional” system by the communist Green Revolution. Particular attention is given to technological materialities, including the physical actions of rice technologies on the material world and the physical aspects of rice technologies (or the way they are made and used). The article's main theoretical goal is to develop an approach to technological transformation that brings the study of human-environment relations more firmly onto the study of technological materialities and technological systems. It is suggested that all technological systems are eco-technological systems, that is, ecologically grounded human-built environments.