In this paper, first of all the concept of hedge mentioned in previous studies has been established. Second of all, by referring to the hedge appearing in Chinese journals of linguistics and sociology have been newly classified by Genre-Based Approach and the characteristics of hedge have been analyzed. Hedge is largely classified into 2 parts, Content-oriented and Additional ones. Content-oriented one consists of 4 sub-parts in detail, Quotation/ Evidence Hedge, Evocativeness Hedge, Subjectivisation Hedge, and Objectification Hedge. Additional ones are composed of 3 sub-parts, Nonquantifiable Heage, Unidentifiable hedge, and Uncertainty Hedge. In academic papers, hedge generally keeps an author from laying out his emotions or descriptions in order to reduce the antipathy, to represent his courtesy, politeness, and positive attitude to readers, and finally to induce positive acceptance in expressing his opinion and idea. As a linguistic regulator which can control connotations and intensity of language, hedge have the ability to reinforce the issue depending on the context. It could also mitigate his concern about incomplete understand of previous studies and not fully reviewing mass data. In an academic paper in China, although hedge in linguistics is used passively and can be mainly found in indirect evaluations on the amount of prior studies, hedge in sociology are used actively and can be easily found in direct evaluations of both amount and quality. Hedge is more frequently used in sociology than linguistics.