Critical Discourse Analysis (CDA) which is also called Critical Linguistics (CL). CDA aims at identifying and analyzing the ideological assumptions and power relations underlying in the discourse.The thesis uses the Systemic-Functional Grammar to reinforce the Three Dimensional Concepts and tries to explain the power relations and the ideologies hidden in the political speeches. At last, the thesis tries to reveal how political speakers achieve their goals by the use of language.The followings are the creative points of the thesis. Firstly, Most of the previous theses about CDA mainly focus on the news analysis. However, the analysis about political speech is not large in number. The previous CDA theses about Obama's speech only choose the inaugural address speech as the analysis data and then draw a conclusion. This kind of conclusion is not very persuasive and convincing. In order to make the conclusion of the thesis more acceptable, the thesis chooses ten speeches in Obama's race speeches for 2008 American Presidential Election in order to unveil the ideologies hidden in the speeches and also figures out that how the politicians advocate their democracy, freedom, equality and human rights, and how they gain the support of their people with the help of language. Secondly, In order to make the related numbers appear in the thesis more precise and persuasive, the Corpus Linguistics'methods are used to analyze the thesis. This is another creative point of the thesis. |