An abstract is a brief summary of a research paper, review or conference proceeding, which can be considered as a sub-register of academic writing and is often used to help readers quickly ascertain the paper's purpose, thesis, main results and conclusions. With the development of international academic communication, English abstracts play an increasingly vital role in international publishing and academic papers, being the basis for international academic citation indexes. UNESCO prescribes that all published scientific articles, no matter in which language, require a succinct English abstract. Most literature database search engines, such as the EI index, only display abstracts rather than providing the full text of the paper. Since an unsuccessful English abstract would be detrimental to the whole paper as well as to the general quality of the journal, no academic authors would want to lower their guard. In this context, the study of linguistic features of academic abstracts has attracted more and more attention of EAP scholars. The studies on English abstracts in China mainly focus on the writing paradigm as well as such linguistic features as stylistics, textual coherence, grammatical patterns, tense, voice and usage of prepositions (Xiong, 2002; Li et al, 2004; Wang, 2005; Fan, 2006; Li, 2008; He & Cao, 2010).