Abstract: The catchword is popular just because of its process of constructionalization. It comes into language system in the form of catchword construction. The main mechanism of catchword constructionalization is meme, a culture gene which survives by imitation and transmission. The primary factor of catchword formation is the potential meme which consists information about dominant culture, zeitgeist, special expressions and so on. These potential memes turned into strong memes by trigger mechanism in the language information processing, entering language net system, producing new language node relation of natural type hierarchy. The copy and imitation of language information appears to be gradient evolution. The copy and transmission procession produces new catchword cluster, forming type construction which not only reflects the generalizing nature of constructionalization but also its characteristics of schematicity, productivity and compositionality.