Politeness is one of the important language behaviors used to maintain social order.As a universal phenomenon,politeness plays a crucial role in helping maintain social harmony and friendly interpersonal relationships.In different languages,pragmatic difference clearly exits.Not only the politeness principles are different in English and Chinese,but also the practical use.For example,compliments,responses,addresses,euphemisms and greetings.This paper aims to make a contrastively pragmatic study of politeness between the American English and Chinese to discuss their pragmatic differences and analyze the different politeness principles in both languages.The main courtesy language in some situations and a contrastive analysis concerning cultural values between the two languages are included.The paper aims to discover the distinctions between the two different cultures and point out the significance of politeness in the cross-cultural communication and English teaching. Politeness is one of the important language behaviors used to maintain social order. As a universal phenomenon, politeness plays a crucial role in helping maintain social harmony and friendly interpersonal relationships.In different languages, pragmatic difference clearly exits. Not only the politeness principles are different in English and Chinese, but also the practical use. For example, compliments, responses, addresses, euphemisms and greetings. This paper aims to make a contrastively pragmatic study of politeness between the American English and Chinese to discuss their pragmatic differences and analyze the different politeness principles in both languages. main courtesy language in some situations and a contrastive analysis concerning cultural values ​​between the two languages ​​are included. the paper aims to discover the distinctions between the two different cultures and point out the significance of politeness in the cross- cultural communication and English teaching