Although traditional grammar regards noun phrases (NPs) as generally unable to be modified by adverbs and vice versa, numerous "Adverb + NP" structures have emerged in literary works, news media, etc. since the mid‐20th century. Among them, "Hen + NP" structures are particularly prominent. As analyzing such special language phenomena from the perspective of decategorization may offer new insights, this study examines the functional shift of NPs in the distinctive "Hen+NP" structure using decategorization theory. Through the analysis of 15 examples from the CCL and BCC corpora covering reliable sources including literary works and news reports, the cognitive processes underlying the functional shift of NPs are interpreted and summarized, along with discussion of the potential mechanisms and relative characteristics. By exploring decategorization on different levels, this study aims to present a novel approach to investigating the phenomenon of NPs modified by the Chinese degree adverb "Hen", as well as enrich the research based on decategorization theory.