【正文】 ciple: Correctness, Conciseness, Clearness, Completeness, Concreteness, Courtesy, Consideration(Sperberamp。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 would be interested in receiving your inquires for all kinds of chemicals(Yu Guixia, 2007:12). Using” all kinds of “ the additional vague word reflects that the writer doesn’t know what kind of information the reader are interested in, at the same time, he hopes to establish a good business relationship with the opposite party.Selfprotection. One of the most important purposes of the use of vague language in business correspondence is to strengthen selfprotection. In business activities, because things are unpredictable and changeable and so on, the writer often can’t give accurate answer in terms of customer’s requirements. In such circumstances, the writer had better use vague language to avoid wrong answer and the impact of their own interests. In addition, if the clients themselves require to bear some responsibility, or the information provided by them will make negative effects to other customers to some extent or will produce direct economic loss, this time using vagueness is a very good means for selfprotection. Example4: This product may be of magic in the temporary relief of the symptoms monly associated with frozen shoulder(Yu Guixia, 2007:12).The writ