Abstract: Based on the empirical research and a small self-built corpus, the paper attempts to explore generic structure of the psychiatrist-psychopath institutional conversation and its functional varieties from genre theories of Systemic Functional Linguistics.The research results reveal a four-stage structure mark:orientation^medical history collection and professional inspection^diagnostic statements and treatment recommendations^coda.In the lexical-grammatical realizations, this structural potential can be achieved through a mixing of discourse patterns.Among which some are congruent and others metaphorical.While representing the characteristics of the psychiatrist's repertoire and genre identity,they also reflect the psychiatrist's genre purposes in specific context.