Abstract:  Politeness is one of the means to ensure the success of the communication among human beings and has attracted wide attention from the academics. English business letters, an important method of international communications, can not only convey information, but can be used to establish and strengthen the relationships between the two parties. Thus politeness has been placed high expectations on. Leech’s politeness principle and Brown and Levinson’s face theory serve as underlying principles in our analysis. Based on these theories, this essay mainly focuses on the linguistic realization of politeness strategies in good-news and bad-news business letters with regard to lexical, syntactic, and discourse level in the hope of finding out why and how politeness strategies are applied to achieve politeness and facilitate the successful and efficient business transactions.

Key words: politeness, Leech’s politeness principle, face, good-news letters, bad-news letters.

摘要：礼貌是确保人类顺畅成功交际的基本手段之一,自上世纪七十年代以来引起学术界广泛关注。英文商务信函作为商务交流的一种重要方式,不仅具有传递信息的功能,还担负着建立、加强业务联系的重任,因而对礼貌具有较高要求。本文将以Leech 的礼貌原则及Brown 和Levinson 的面子保全论为理论基础,从词汇，语法以及篇章结构三方面探讨礼貌策略在好消息与坏消息信函的不同应用，分析礼貌策略如何在这两种信函中实现礼貌以及成功达成交易。

关键词：礼貌、Leech 礼貌准则、面子、好消息信函、坏消息信函