| Abstract in English | 第5-6页 |
| Abstract in Chinese | 第7-12页 |
| Chapter 1 Introduction | 第12-17页 |
| 1.1 Background of the study | 第12-14页 |
| 1.2 Significance of the study | 第14-16页 |
| 1.3 Overall structure of the thesis | 第16-17页 |
| Chapter 2 Literature Review | 第17-36页 |
| 2.1 Concept of cohesion | 第17-19页 |
| 2.2 Halliday and Hasan’ cohesion theory | 第19-21页 |
| 2.3 Taxonomy of cohesive devices | 第21-29页 |
| 2.3.1 Grammatical cohesion | 第21-26页 |
| 2.3.2 Lexical cohesion | 第26-29页 |
| 2.4 Previous studies on cohesion and writing abroad and in China | 第29-36页 |
| 2.4.1 Previous studies on cohesion and writing abroad | 第29-32页 |
| 2.4.2 Previous studies on cohesion and writing in China | 第32-36页 |
| Chapter 3 Research Design | 第36-41页 |
| 3.1 Research questions | 第36页 |
| 3.2 Corpus adopted in the present study | 第36-37页 |
| 3.3 Instruments | 第37-38页 |
| 3.4 Data collection | 第38-40页 |
| 3.5 Data analysis | 第40-41页 |
| Chapter 4 Results and Discussions | 第41-58页 |
| 4.1 The differences in the frequency of cohesive devices used in the writings ofstudents at different grades | 第41-44页 |
| 4.2 The differences in the frequency of cohesive devices used in the writings ofstudents in the high-score group and the low-score group | 第44-48页 |
| 4.3 The differences in the frequency of cohesive devices used in the writings ofdifferent genres | 第48-58页 |
| 4.3.1 The differences in the frequency of cohesive devices in argumentationand narration | 第48-51页 |
| 4.3.2 The differences in the frequency of cohesive devices in argumentationand exposition | 第51-54页 |
| 4.3.3 The differences in the frequency of cohesive devices in exposition andnarration | 第54-58页 |
| Chapter 5 Conclusion | 第58-63页 |
| 5.1 Major findings of the study | 第58-59页 |
| 5.2 Implications of the study | 第59-61页 |
| 5.2.1 Implications for instructors | 第59-60页 |
| 5.2.2 Implications for English learners | 第60-61页 |
| 5.3 Limitations of the present study and suggestions for future study | 第61-63页 |
| Bibliography | 第63-68页 |
| Acknowledgments | 第68-69页 |
| Appendi x | 第69-71页 |
| Academic Achievements | 第71页 |
