【Abstract】Politeness Principle （PP） is an important concept in the field of pragmatics. In the process of verbal communication， people who follow the principle of politeness can help them express different mental thought. However， there are some gender differences in the use of PP in every expression. Through the observance and violation of PP by men and women， it is found that women are more polite than men and their words are more decent and the reasons for the formation of gender differences in language and some suggestions for achieving successful verbal communication between men and women.
　　【Key words】Politeness Principle； Gender Differences； Mental Thought； Expression
　　In modern society of globalization， polite language provides a guarantee for people to establish friendly social relations. In the process of communication， people’s language is often affected by various factors. In real life， different people’s language presents different mental thoughts. Especially the men and the women， they show differences in language strategies and performances in their daily conversations. Therefore， in the use of politeness principles， it is necessary to study gender differences in conversations.
　　Case Study of PP from Men & Women
　　Leech divided Politeness Principle into six maxims： Tact Maxim， Generosity Maxim， Approbation Maxim， Modesty Maxim， Agreement Maxim and Sympathy Maxim. In the actual conversation， men and women to comply with and contrary to the principle of politeness is not the same. The following examples are used to specifically analyze the differences between men and women in the use of PP. （A to represent the man and B to represent the woman.）
　　1.Tact Maxim and Generosity Maxim
　　Example： When people encounter bad things， men and women are expressed in different ways.
　　A： Shit！
　　B： Oh， my god！
　　In daily conversation， women instinctively avoid vulgar， filthy and abusive language， while men often use taboos and idioms such as shit， fuck， damn. Even to vent， women also like to use its more elegant variant or euphemistic， indirect expressions. Therefore， women often follow the Tact Maxim， while men are the opposite. Women use more polite language， because they try to use polite language to maintain and develop this relationship （朱凡， 劉芳， 倪丹萍， 2008）. They emphasize the emotional function of the language， pay more attention to the feelings of the speaker， like to encourage others to continue a friendly conversation. While men use language as a tool to acquire or disseminate information. They want to self-expression in front of the public in order to improve their status and fame.