| Acknowledgements | 第1-5页 |
| Abstract | 第5-7页 |
| 摘要 | 第7-13页 |
| Chapter One Introduction | 第13-16页 |
| ·Background of the study | 第13页 |
| ·Necessity and significance of the study | 第13-14页 |
| ·Purpose of the study | 第14-15页 |
| ·Overall structure of the thesis | 第15-16页 |
| Chapter Two Literature Review | 第16-27页 |
| ·Notion of lexical bundles | 第16-22页 |
| ·Definition of lexical bundles | 第16-17页 |
| ·Classification of lexical bundles | 第17-22页 |
| ·Previous empirical studies on lexical bundles | 第22-27页 |
| ·Empirical studies on lexical bundles abroad | 第22-24页 |
| ·Empirical studies on lexical bundles at home | 第24-27页 |
| Chapter Three Research Methodology | 第27-35页 |
| ·Research questions | 第27页 |
| ·Corpora used in the study | 第27-28页 |
| ·Tools and procedures for data processing | 第28-35页 |
| ·AntConc | 第29页 |
| ·Log-likelihood ratio test | 第29页 |
| ·Procedures for data processing | 第29-35页 |
| Chapter Four Results and Discussion | 第35-62页 |
| ·Distribution of lexical bundles in NNSC and NSC | 第35-37页 |
| ·Most frequently used lexical bundles in NNSC and NSC | 第37-40页 |
| ·Structural and functional analysis of 4-word lexical bundles in NNSC and NSC | 第40-62页 |
| ·Structural analysis of 4-word lexical bundles in the two corpora | 第41-52页 |
| ·Functional analysis of 4-word lexical bundles in the two corpora | 第52-62页 |
| Chapter Five Conclusion | 第62-66页 |
| ·Major findings of the study | 第62-63页 |
| ·Implications of the study | 第63-64页 |
| ·Limitations and suggestions for further research | 第64-66页 |
| References | 第66-70页 |
| Appendices | 第70-77页 |
| Appendix A References for native scholar writing corpus | 第70-74页 |
| Appendix B The complete list of 4-word lexical bundles in NNSC | 第74-75页 |
| Appendix C The complete list of 4-word lexical bundles in NSC | 第75-77页 |
| Publications | 第77页 |
