The Baron in the Trees,one of the Our Ancestors Series,is a novel written by Italo Calvino.In this book,picture,emotions and scenery are intertwined with the text,consequently scenes are ex-quisitely depicted,emotions are intensely rendered,even evoking a vivid picture.The mechanism of figure-background conversion helps readers focus on the figures constantly,which makes it possible to generate an original as well as interesting reading aesthetic experience in the cognitive process of reading.This paper,employing one approach of cognitive poetics,close reading,is based on the figure-background theory,which contributes to analyzing the figure-background dynamic conversion mechanism in The Baron in the Trees,ie,the figure is usually more prominent than the background;the figure often converts into the background with the unfolding of the plot,and vice versa;figure-back-ground theory can be used for characters analysis because some characters fall into figurative charac-ters and some characters are grounding ones,and it is likely for them to reverse into each other under certain circumstances.In some cases,there exist both positive and negative figures,which complement each other.Moreover,specific figure strengthening strategies manage to attract the reader's attention.