Argumentation has been considered one of the priorities in education. This paper will examine the functions of argumentation from different disciplines and the reason why argumentation should be a part of the curriculum in Hong Kong. The paper's focus is on various conceptualizations and some of the key concepts of argumentation as critical thinking. The paper involves a critique of some theoretical frameworks for the study of argumentation. A brief comparison will be made between Chinese and Western conceptualizations of argumentation in order to suggest a comprehensive theory to inform curriculum practices. Some student texts, which were taken from my qualitative research, will be used to illustrate some key concepts in argumentation and the need for adequate evidence and critical thinking in the construction of effective writing. The pedagogical implications for the teaching of argumentation are discussed.