Academic discourse is the product of agreement negotiation among members in academic communities. The primary rhetorical function of academic discourse is to persuade the readers into agreeing upon the writers' claims. This rhetorical function can be embodied through textual linking and stance expressing realized by linguistic devices. Metadiscursive nouns, as an extension and supplementation of metadiscourse, combine these two functions and contribute to the cohesion of textual organization and the conveying of writers' stance. This study explores the difference in the employment of this linguistic device in PhD dissertation written by Chinses advanced English learners as novice writers and research articles published in international journals written by expert writers in the field of foreign linguistics and applied linguistics. The purpose of this study is to reveal the different ways of knowledge construction by means of metadiscursive nouns in the two genres and the interactional conventions embedded in the academic communities. Explicit instruction strategies are provided to enhance the pedagogical practice in academic writing.