摘要:This paper profiles the pathway from Bernstein’s code theory and knowledge structure to Halliday’s grammatical metaphor. It firstly delineates the theorizing of code theory and knowledge structure, and subsequently describes the process of associating itself with Karl Maton’s legitimate code theory. Finally, drawing upon the semantic dimension of legitimate code theory, that is, semantic density and semantic gravity, Halliday’s grammatical metaphor is expounded sociologically.