Brandom claims that his inferential semantics has its roots in traditional philosophy. Especially he interprets Kant as one who took the lead in two important turns in the history of philosophy, both of which wielded great influence on his inferential semantics, i.e., a propositional turn and a semantic turn. Of these, the latter is what this paper is concerned with. On the basis of Kant’s statement that concepts are rules, Brandom credits Kant with taking concepts to be norms according to which the judgmental contentfulness is evaluated. The purpose of this paper is to examine how such an interpretation can be justified in Kant’s system of philosophy. For this purpose, this paper first tries to outline Brandom’s interpretation on Kant(Ch.II), and to show how his interpretation can be generally accepted in Kant’s philosophy(Ch.III). Then, this paper argues that categories whose special status may be an obstacle to his interpretation can also be regarded as normative from a transcendental perspective, even though constitutive from an empirical perspective(Ch.IV). Finally, we conclude this paper by briefly suggesting some significance of Brandom’s interpretation with regard to our present understanding of Kant(Ch.V).