本研究通过对比分析20篇以英语为母语和20篇以汉语为母语的英语专业硕士学位论文中的“讨论”部分，旨在探讨以英语为母语的外国学生和以汉语为母语的中国学生在构建此部分学术写作过程中语类结构选择和语言特征的异同。以Yang and Allison (2003)所提出的“二级语步和步骤模式”（two-level Move and Step framework）为主要分析方法，在体现语类结构的宏观层面上，本研究主要对比分析了两类语篇中所出现的语步、步骤和语步循环模式；在体现语言特征的微观层面，本研究重点分析了两类语篇中转述语和模糊限制语的使用特征。分析结果表明，在宏观的语类结构层面，中国学生的语篇中有四个常用语步：“背景信息”、“汇报结果”、“评论结果”和“研究启示”。在外国学生的语篇中，除了以上四个常用语步外，“总结研究”和“评价研究”的应用也非常广泛。其中, “汇报结果” 和“评论结果”在所分析中国学生和外国学生的每一篇语篇中都有应用，而且语步“评论结果”所包含的四个步骤“阐释结果”、“比较相关文献”、“解释结果”、和“评价结果” 的出现率也都在75%以上，说明在以上诸方面中国学生论文的“讨论” 部分与本族语写作者的基本相符。在语步循环模式方面，虽然中国学生和外国学生论文中出现的语步循环总数大体相同，但外国学生论文中的语步循环模式种类却比中国学生论文中的更加多样化。在微观的语言形式层面，转述语和模糊限制语在两类语篇中都得到了广泛应用，但却表现出了不同的特征。在转述形式和转述动词的时态选择上，中国学生倾向于选择一般现在时并将转述作者作为“主语—动作者”置于句首，表明其有意突显转述作者的权威性并对所转述内容的正确性深信不疑。而外国学生大多选择一般过去时和非作者嵌入/非转述动词的转述形式，表明其只客观强调转述内容相对于原研究的真实性。在模糊限制语的使用上，中国学生不仅使用模糊限制语的频率不及外国学生高，而且使用的模糊限制语种类也不如外国学生丰富多样，说明中国学生对模糊限制语的应用还不够熟练。综上所述，本研究的发现有利于了解中国学生和外国学生在构建硕士学位论文“讨论”部分时的差异，对如何更好地指导中国学生的论文写作，使之更好地遵从英语学术写作规范有一定的指导意义。

The main purpose of this study is to give a contrastive genre analysis of MA thesis discussions written by native English students and Chinese English learners majored in applied linguistics. To this end, a NES (Native English Speakers) corpus and a CEL (Chinese English Learners) corpus, each including 20 MA thesis discussions, was first set up. By referring to Yang and Allison’s (2003) two-level Move and Step framework, moves, constituent steps and move cycles in the two kinds of thesis discussions were first identified and analyzed to reveal their macro-level generic structures. Then, micro-level linguistic features related to the moves and steps, especially citations and hedging expressions, were also examined and compared. The results show that the generic structures of the NES and CEL MA thesis discussions exhibit both differences and similarities. On the macro-level, four stable moves are identified in the CEL corpus: Background information→Reporting results→Commenting on results →Deductions from the research, and six stable moves are found in the NES corpus: Background information→Reporting results→Commenting on results→ Summarizing the study →Evaluating the study → Deductions from the research. Among all the moves and steps identified in the two corpora, Reporting results and Commenting on results appears to be the only two obligatory moves, indicating that both Chinese students and native English students have attached great importance to commenting on their research results in the MA thesis discussions. One big difference between the two corpora is the absence of Summarizing the study and Evaluating the study in the CEL corpus, which, upon further analysis, could be attributed to the presence of a Conclusion section after every CEL MA thesis discussion. Moreover, the move cycle patterns identified in the NES corpus are more diversified than that of the CEL corpus, suggesting that the cyclicity of moves in the NES corpus is much more complex and native English students might have constructed their MA thesis discussions in a more intricate and complicated way. On the micro-level, the analysis of citations shows that while native English students employ non-integral/non-reporting structures more often, Chinese students are in favor of integral/reporting structures to emphasize the authority of the reported author. Regarding the tense forms of reporting verbs in the two corpora, the most common choice in the CEL corpus is the simple present while the most common one in the NES corpus is the simple past, indicating that Chinese students tend to accept what they have cited as a current state of fact and the native English students are more likely to treat what they cite as restricted to specific study. The analysis of hedging devices reveals that native English students employ hedging devices more frequently and therefore are somewhat more tentative and cautious than Chinese students in interpreting the research results. Moreover, a close examination of all hedging devices in the two corpora also reveals that native English students not only employ hedging devices more frequently but also employ a larger variety of hedging devices than Chinese students, indicating that Chinese students might not be as proficient as NES students in expressing hedging. In conclusion, by examining the similarities and differences between the generic structures of the NES and CEL MA thesis discussions, the present study provides an insightful view on how Chinese students construct their MA thesis discussion and is of significance in introducing a genre-based approach to the teaching of academic writings in China.