The purpose of this essay is to study the iconicity of James Joyce’s Finnegans Wake. The iconicity is the similarity or analogy between the form of a sign and its meaning. It is usually divided into two different types: the imagic iconicity and the diagrammatic one. The two types of it can be applied to analyze and explain some characteristics of the major characters of Finnegans Wake. In the novel, many of the characters morph into other characters from scene to scene, and the two main characters, HCE and ALP, seem to be divided into separate sides of their personality. The multiplicity of their incarnations makes it difficult to identify them in the same way as characters in traditional fiction. The portmanteau word of Finnegans Wake challenges two myths on which most assumptions about the efficacy of language rest. The writer James Joyce used a lot of icons, indices, and simbols(sigla), blending the reality of life with a dream world. He also created a few diagrams or signs for the chief characters, e.g., ⴜ(HCE), △(ALP), ⼕(Shem), ∧(Shaun), and ⊣(Issy). As an experimental novelist, Joyce exploited the iconic aspects of letters and ciphers to go beyond the limits of traditional language.