The aim of this paper is to introduce and evaluate the Cardiff Grammar, which is treated as a component of M.A.K.Halliday's Systemic Functional Linguistics.The paper begins with a short biography of Robin Fawcett's life, and goes on to describe his research background, his relationship with M.A.K.Halliday, the Cardiff research group, the major publications by people working in the framework of the Cardiff Grammar, etc.It also discusses the relationship between the Cardiff Grammar and Halliday's theory of language.