Abstract: The paper centers on comparing Sino-American public service advertisements in language structures, rhetorical devices and themes of public service ads. And based on the difference, it tries to disclose the causes of the differences in terms of the Chinese and American culture. It is found that  public service advertisements are a reflection of the cultural differences between China and the United States. It shows the different theology, values,  thinking modes and aesthetics between two countries. Finally, it concludes that public service advertisements, as a form of social culture, embody the unique culture of a nation.

Key words: public service advertisement; cultural difference; thinking mode

摘要：本文通过对中美公益广告语的语言结构、修辞手法及广告主题三个方面进行对比，并在此基础上从文化角度揭示了中美公益广告差异的原因，文章显示了中美文化在理念、价值观念及思维方式上的差异。最后文章得出结论，公益广告作为一种文化形式包含了一个国家独特的文化内涵。

关键词：公益广告；文化差异；思维方式