【正文】 e participants are monly regard as the addresser and the addressee. In business munication, business correspondence is used to sell products or services, request material or information, answer customer inquiries, maintain good public relations, and serve a variety of other business functions(Channel 1994: 20). Features of English business correspondenceEnglish business correspondence is an effective way to express and keep information in business contacts, which can be roughly divided into the following parts: Letter to establish business relations, Information advisory letter, Valuation and quotation letter, Letter fot order, Processing business letter, Claims and plaints letter after business transactions. Business letters ate more formal official documents with correct words and succinct writing style. Business correspondence generally follows the writing principles of business English, that is, “7cs” principle: Correctness, Conciseness, Clearness, Completeness, Concreteness, Courtesy, Consideration(Sperberamp。第四章主要總結(jié)了本篇論文的局限性以及意義。關(guān)聯(lián)理論認(rèn)為，語言交際是個(gè)明示推理過程，發(fā)話人應(yīng)該提供盡可能關(guān)聯(lián)的信息，使聽話人能夠以最小的努力去理解發(fā)話人的含義，達(dá)到最佳的語境效果。本文從關(guān)聯(lián)理論角度探析外貿(mào)英文信函中的模糊語現(xiàn)象，運(yùn)用關(guān)聯(lián)理論首先解釋了商務(wù)英語信函中的語言模糊現(xiàn)象，然后以真實(shí)的商務(wù)信函為例子，探討了寫信人如何使用模糊語言明示話語信息，實(shí)現(xiàn)最佳關(guān)聯(lián)，以準(zhǔn)確表達(dá)交際意圖，達(dá)到交際目的，使貿(mào)易雙方之間達(dá)成互明，實(shí)現(xiàn)成功交際的目的。此篇論文旨在使商務(wù)交際中的貿(mào)易雙更好的交際與理解對(duì)方，使得交際雙方更好的使用模糊與建立良好的商務(wù)關(guān)系。Wilson1986:40). Business English must be expressed accurately and clearly to convey information and be careful of using metaphor, hyperbole and so on. It should try to avoid using uncertain words, in order to avoid unnecessary disputes ,because business letters are usually used to be the basis of determining the rights and obligations of the parties. Vagueness Overview of vaguenessThe study on vagueness has been a long time. But there isn’t an uniform definition up to now. As the famous philosopher Pierce first pointed out in 1902, “ A proposition is vague where there are possible states of things concerning which it is intrinsically uncertain whether, had they been contemplated by the speaker, he would have regarded them as excluded or allowed by the proposition”(Pierce, 1902:749). Crystal and Davy from the perspective of Applied Linguistic, pointed out four reasons that language users use vague language. The reasons are the lack of memory, lack of accurate and appropriate words, inaccurate topic, intent expression for specific meaning or avoiding statementing accurate information. Channell(1994:20)proposed three kinds of vagueness: (1) additional vague words, refers to the words which are added before or after the words, in order to make statements bee blurred. Like, around, some, kind of, nearly and so on. (2) vague words, refers to the meaning of words that are vague in itself. Like, thingummy, whatsit, loads, heaps of and so on. (3) vague implication, refers to accurate expression that contains fuzzy implication. Like, Odessa has a population of one million. The one million is an accurate number which doesn’t mean the population of the city is really one million.With the further study of vagueness, people gradually realize the important and unique pragmatic features in language munication. Such as, it can make language more persuasive and polite, or the speaker for selfprotection deliberately uses vague language to cover specific information. Therefore, vagueness is not only a linguistic phenomenon, but also a language strategy. Nowadays, international trade is increasingly frequent, business English letters have bee an important means of munication in the economic field. Pragmatic analysis of vagueness in business correspondence Being polite. Language munication is a necessary means to exchange feelings. In front of the feelings of things, vagueness can harmonize the relationship. The primary basis of English business correspondence is appropriate and polite language, the use of vague words can make words euphemistic and gentle. Especially for some sensitive topics, such as, the interests of both sides, the focus of conflict. Vagueness can avoid conflicts and make diversionary effect. Sometimes for the moderate and courtesy consideration, the use of vagueness is good for both parties of trade. Example1: If possible, please also send me samples of the goods you are interested in selling(Li Li, 2008:231233). The writer really hopes that the reader can send him the samples he is interested in as soon as possible. But the direct expression will make words crude, leaving an unfortable feeling for the reader. Using “if possible” here can make words more euphemistic and gentle. Being persuasive. One of the basic requirements of business letter is true and correct. Based on this situation, using vagueness can be more likely to arouse the reader’s interest or persuade them to accept his views.Example2: We are very well connected with all the major dealers here of industrial products(Yu Guixia, 2007:12). Additional vague language” very well ” makes the relationship between the writer and the reader closer, this relationship has made a good foundation for bilateral cooperation. The vagueness here makes the whole statement more persuasive.Lack of specific information. American philosopher . Grice pointed out in a series of lectures in Harvard University in 1976, in the process of munication, in order to guarantee the smooth progress of the session, both sides must abide by some basic principles, namely the Cooperative Principle. And he put forward four criteria or implementations of cooperative of principle: the maxim of quantity, the maxim of quality, applicable standards and manner maxim. Among them, the maxim of quality requires to make the information provided true and not to speak false words, or the words lack of evidence. Because of the objective things themselves with uncertainty, when writer lacks enough information, the use of vagueness can make statement more objective, accurate and can make the statement kind. Example3: We