‘Invisible cities’ has continued to attract attention since its publication, and its imaginative and thought-provoking writing has been enjoyed by readers.

City as the most significant topic,Calvino was keenly aware of the ethical and social necessity of urban renewal. He chose to theorize and present his concept of utopia in the form of a novel, as a perceptual and cognitive therapy of the imagination, which would enable his readers (or travelers) to envision alternatives to existing urban forms and social practices.

Then, the post-modern presentation of the whole book leaves many readers at a loss, but at the same time, a large number of readers can still extract quotations and sentences from it and gain insights from them. Inspired by such excerpts, a kind of machine approach that encodes text in sentences is applied to uncover implicit themes in the text.