The rapid technological advance in media of interpersonal communication has started to affect the mode of business communication. E-mails have taken the place of mailed letters as well as faxes and become a dominant channel of communicating between business professionals. E-mail, as a new electronic medium of business communication has attracted increasing interest from scholars around the world. Some researchers overseas have identified some distinct linguistic features and rhetorical strategies in authentic business e-mails. However, in China e-mails, especially e-mails in commercial contexts have not received sufficient attention from scholars and the studies on authentic business e-mail data are rarely found. As to the genre analysis of authentic business written corpora, most work overseas focused on business letters, not e-mails and in China most of the written data collected for study are the examples extracted from the published textbooks.In China most export and import companies have adopted e-mail system as one of the major channels for their daily business communications. To a certain extent, e-mail communication has taken the place of face-to-face negotiation. Therefore, this new text type deserves special attention so that some constructive implications on the teaching of business written communication and suggestions on the materials development of BE writing textbooks in China could be made.This thesis firstly attempts to explore the discourse structure of international trade e-mails from a genre perspective to see whether this text type represents a new genre. Then, some distinctive language features of these e-mail messages are described from a stylistic point of view, on the basis of which a comparative study of styles will be conducted between authentic business emails and the "specimen letters" in those textbooks of foreign trade correspondence published in China. Lastly, the thesis makes a comparative analysis of different discourse strategies adopted by sellers and buyers to make requests in business communication from social and cultural perspectives.Based on a detailed analysis of 280 e-mail messages, it has been found that the communicative purpose that motivates the exchange of these e-mails is a successful conclusion of a transaction, from which both the seller and the buyer can make some profits. A unique genre structure of the ITE made of 4 moves has been identified. Based on a combination of quantitative and qualitative analysis of 80 e-mail samples, it is concluded that ITE has combined the language features of both spoken and written discourse, which makes its style more formal than personal e-mails but less formal than business letters writing. It is also found that the old-fashioned commercial jargons or cliches are employed rather frequently in the course books while such expressions were rarely found in the real email data. Through a quantitative analysis, it is found that though power and distance do have some effects on certain linguistic choices made by business professionals to make requests, the way to issue requests is affected mostly by the institutional conventions, like the rule that efficiency is considered to be the most important principle to guide business written communication.