Abstract: This paper attempts to deal with a controversial problem in current research of metaphor, that is, the iconicity of metaphor. The author argues that imagery is a crucial mechanism in the comprehension and the imagery content of a metaphor constitutes the non-propositional meaning of the metaphor whose existence has long been denied by the traditional theories. To examine this problem, the author first reviews the main findings in the relevant literature and then builds a semiotic model of metaphor, in which the role of imagery can be easily detected. Both the linguistic data and the experiment provide ample evidence in favor of our argument. This study is significant in that it attempts to explore a hitherto neglected domain of metaphorical meaning.