Parody is a commonly-seen rhetorical act. In parody, the profile model is connected with the noumenon in meaning and linguistics structure, and the former depends on the latter. Similarity between the profile and the noumenon is the basic characteristic of Parody, which is also a cognitive behavior and it can be interpreted within the framework of Conceptual Blending Theory. Guided by Conceptual Blending Theory, this paper analyses the examples of parody and attempts to find out parody's productive motivation. The paper concludes that parody is produced through the cross-space mapping of different mental spaces and composition of new spaces.