作者：蔡天航
　　【Abstract】The speech of Barack· Hussain· Obama’s is praised because of his excellent public speech skills. Therefore， this paper offers an attempt to analyze his style of public speech from phonetic， lexical， sentence and rhetorical devices level in order to understand his style of public speech.
　　【Key Words】Barack· Hussain· Obama； campaign winning speech； stylistic analysis
　　【作者簡介】蔡天航（1994- ），女，苗族，贵州人，中央民族大学，在读研究生，研究方向：翻译理论与实践。
　　1. Introduction
　　Public speech， as a special style of writing， is different from the oral genres such as daily conversation， as well as literary genres such as novels， plays and poems. It combines the linguistic features of both spoken and written forms of writing， and at the same time has a clear difference from the two forms of writing. The speech delivered by Barack Obama is quite appealing as his speech includes his gratitude to supporters， showing his determination and confidence to the audience.
　　2. Sound level
　　This fragment has 2047 words in total. The duration of the speech is 20 minutes. Therefore， the speech rate of this fragment is slower. It will not only help the speaker to express his point clearly， but also help the audience to think about these points of view.
　　Pause has also been used many times in this speech. There is almost a pause in each sentence， giving the audience enough time to think and understand the content and speaker’s intentions.
　　3. Lexical Level
　　3.1 Vocabulary difficulty
　　According to Qian Yuan， the difficulty index of an easy-to-understand speech is about 10. In this passage， the difficulty index of the speech is 7.74. It shows that the overall Obama speech is easy to understand and acceptable because his speech is aimed at the entire American public.
　　Difficulty index（Fog Index）=0.4（H+L）（Qian Yuan，，1991）（L= average sentence length；H=difficult word ratio）
　　difficult word ratio =（difficult word total / Word total）×100%
　　3.2 Personal Pronouns
　　Another feature of this speech’s vocabulary is the use of personal pronouns. In this speech， the most frequently used personal pronouns is first person. It is used 128 times， accounting for 67.72% of the usage of total personal pronouns. And the second person is used 35 times， accounting for 18.52%， while the third person used less， 26 times， accounting for 13.76%. The frequent use of “I” and “We” makes the information more specific and personal， creating a more intimate feeling， shortening the distance between the speaker and the audience emotionally.