外壳名词大量存在于学术体裁中，因其独特的人际功能而具有重要的研究价值。本文采用语料库方法，以工学期刊英文摘要中的外壳名词为研究对象，对比中国作者和本族语作者外壳名词的使用差异，着重考察各语步上外壳名词的立场建构及人际表达功能。结果表明：中国作者所使用的外壳名词在总体使用频率上远少于本族语作者，且各语步上，二者对外壳名词的使用数量以及通过外壳名词所表达的立场和评价也表现出差异。背景语步和目的语步上，中国作者对评判事物特征的外壳名词使用不足；方法语步和结论语步上，中国作者外壳名词的使用数量总体偏少，还需增强外壳名词的立场构建意识。该研究的发现有助于二语学习者恰当使用外壳名词，提高学术英语写作水平。

Shell nouns are widely found in academic English writing. With their stance-taking and impersonal functions, research on shell nouns is of great importance. This paper takes English abstracts from engineering journals as the subjects and applies a corpus-based analysis to explore the differences of shell nouns used by native speakers and Chinese learners. It focuses on stance construction and interpersonal interaction in different moves. The results show that shell nouns used by Chinese learners are much less than those by native speakers in the total frequencies, and in each move, there are differences between them in the amount and the interpersonal functions of the shell nouns. In Background move and Purpose move, Chinese learners underuse shell nouns with the function of describing attributes of entities; in Method move and Conclusion move, the amount of shell nouns used by Chinese learners is comparatively less, which indicates that stance construction of shell nouns should be strengthened. The findings contribute to the appropriate use of shell nouns of second language learners and the improvement of their academic writing.