Abstract: Basil Bernstein's sociological pedagogy places language at its first place,attempting to explore social issues such as education failure, cultural reproduction, the construction of pedagogic discourse and the alike. One of the main forces of its research comes from Systemic Functional Linguistics represented by M. A. K. Halliday and Ruquia Hasan. This paper is going to review their study on Bernstein's code theory and then tries to excavate the theoretical foundations and practices for the dialogue between code theory and Systemic Functional Linguistics so as to construe the nature and meaning of code from the perspective of Systemic Functional Linguistics.