| ACKNOWLEDGEMENTS | 第1-9页 |
| ABSTRACT | 第9-10页 |
| 摘要 | 第10-14页 |
| LIST OF ABBREVIATIONS | 第14-15页 |
| HAPTER I INTRODUCTION | 第15-18页 |
| ·Research Background | 第15-16页 |
| ·Data Collection and Methodology | 第16页 |
| ·Research Questions | 第16-17页 |
| ·Overview of the Thesis | 第17-18页 |
| CHAPTER II LITERATURE REVIEW | 第18-25页 |
| ·Related Studies on English Business Letters Abroad | 第18-21页 |
| ·Related Studies on English Business Letters at Home | 第21页 |
| ·Related Studies on SLs and CLs at Home | 第21-23页 |
| ·Comments on Related Studies and the Writer’s Own View | 第23-25页 |
| CHAPTER III THEORETICAL FRAMEWORK | 第25-37页 |
| ·Halliday’s Three Metafunctions | 第25-26页 |
| ·Interpersonal Function | 第26-37页 |
| ·Mood System | 第26-31页 |
| ·The Structure of Mood | 第26-27页 |
| ·The Structure of the Residue | 第27-29页 |
| ·Speech Roles and Speech Functions | 第29-30页 |
| ·Types of Mood Structure | 第30-31页 |
| ·Modality System | 第31-35页 |
| ·Person System | 第35-37页 |
| CHAPTER IV COMPARATIVE ANALYSIS OF THE DATA | 第37-78页 |
| ·A Comparison in Terms of Mood System | 第37-53页 |
| ·Mood in SLs | 第37-46页 |
| ·Mood in CLs | 第46-52页 |
| ·Summary for the Comparison in Terms of Mood | 第52-53页 |
| ·A Comparison in Terms of Modality System | 第53-70页 |
| ·Finite Modal Operators | 第54-61页 |
| ·Finite Modal Operators in SLs | 第54-58页 |
| ·Finite Modal Operators in CLs | 第58-61页 |
| ·Summary for the Comparison in Terms of Finite Modal Operators | 第61页 |
| ·Modal Adjuncts | 第61-67页 |
| ·Modal Adjuncts in SLs | 第61-64页 |
| ·Modal Adjuncts in CLs | 第64-66页 |
| ·Summary for the Comparison in Terms of Modal Adjuncts | 第66-67页 |
| ·Modal-Adverbial Combination in SLs and CLs | 第67-68页 |
| ·Predicators in SLs and CLs | 第68-70页 |
| ·A Comparison in Terms of Person System | 第70-78页 |
| ·Person System in SLs | 第71-73页 |
| ·The First Personal Pronouns | 第71-73页 |
| ·The Second Personal Pronouns | 第73页 |
| ·Person System in CLs | 第73-76页 |
| ·The First Personal Pronouns | 第74-75页 |
| ·The Second Personal Pronouns | 第75-76页 |
| ·Summary for the Comparison in Terms of Person System | 第76-78页 |
| CHAPTER V CONCLUSION | 第78-81页 |
| ·Summary of the Major Findings | 第78-79页 |
| ·Implications of the Study | 第79-80页 |
| ·Limitations of the Study | 第80-81页 |
| REFERENCES | 第81-83页 |
