American presidential inaugural address (PIA)is a very important variety with worldwide influence and long-lasting significance. Its main task and purpose is to outline the main policies of the new government and win people’s support. However, the prerequisite of winning people’s sympathy and support lies in people’s good relationship with and trust in the government. Therefore almost all the speakers resort to “approached-based” positive politeness strategy quite often which performs this function very well. American presidential inaugural address (PIA) is a very important variety with global influence and long-lasting significance. Its main task and purpose is to outline the main policies of the new government and win people’s support. However, the prerequisite of winning people’s sympathy and support almost in people’s good relationship with and trust in the government. Therefore almost all the speakers resort to “approached-based ” positive politeness strategy quite often which perform this function very well.