The transition from "aura" to "dialectical image" is a key to trace the trajectory of Walter Benjamin’s aesthetic thoughts. Benjamin repeatedly specified the connotations, the prerequisites for emergence and the reasons for the disappearance of "aura." As far as artistic problems are concerned, the appearance of aura is closely related to "the semblance of beauty", trance experience and authenticity of things, and the key to this is that the aforementioned factors could ensure the essential distance between the aesthetic subject and the aesthetic object. However, these conditions do not stand under mechanical reproduction technology and aura is destroyed and disappears. As Benjamin’s standpoint of thinking gradually shifted from Jewish theology to Marxism, his attitude towards aura also changed from that of lamenting its disappearance to that of criticizing its ideological characteristics. To further on this, he began to explore the possible form of "post-aura art", i.e., the dialectical image epistemologically based on dialectical materialism.