There has been a long history of the study of metaphorical utterances in China, yet most of the studies have been devoted to the demonstration of the steps and processes for the building up of the utterances, with little attention being paid to the exploration of their operating apparatus. This being the case, the paper makes as the theoretic framework the idea of symbolic thinking and the theory of duality of perceptual content , in order to build up a working mechanism of metaphorical expression . Firstly, a structure is abstracted as“(T) → [rewritten as] S”; then the concept of duality of perceptual content in the theory of sensorimotor contingency proposed by the American philosopher Alva Noë is cited for the discussion of the possibility of T being rewritten as S under certain conditions; and then the idea of symbolic thinking is put forward for the explanation of the symbolic relationship between S and the implicit T; and lastly an explanation is given of why T can be emerged as S in the conditions of contexts and intentionality.