ABSTRACT
Critical Discourse Analysis ( CDA) attempts to uncover the inequality in social reality and the way language presents power and ideology through the analysis of language features. Systemic functional linguistics ( SFL) focuses on the dialectical relationship between language and society and has been considered an important approach and theoretical basis to CDA. Doctors in Chinese medical clinic follow the Four Diagnostic Methods, within which the inquiry diagnosis strongly shows the fact that doctor and patient clash over the ideology and strug-gle for the power via language. The study carries out CDA on doctor-patient discourse in Chinese medical clinic within the theoretical framework of SFL from four aspects including nominalization, classification, transitivity and mood, which verifies that the language is the product of asymmetric power between doctor and patient. It is hoped that the paper would provide insight into CDA on doctor-patient discourse and would be of theoretical meaning.