Drawing on MacIntyre's notion of rationality, this article examines the conceptions and practices of critical thinking in Chinese schools. Focusing on the perceptions of school leaders in Shanghai, this study reports that they interpreted critical thinking primarily as personal inquiry and problem solving. They drew attention to the promotion of critical thinking under the current education reform and highlighted ongoing challenges arising from the high-stakes assessments and prevailing socio-cultural values. This paper shows that definitions and applications of critical thinking in Chinese schools are rooted in and shaped by socially embodied and historically contingent traditions. Cultural influences are manifested in an exam-oriented system, an emphasis on didactic teaching, the centrality of textbooks, a non-confrontational view of critical thinking, and a hierarchical relationship between the teacher and students. The example of Shanghai foregrounds the existence and legitimacy of diverse approaches to and expressions of critical thinking across contexts.