The author believes that in the era of post financial crisis，the United States is not in a situation of decline. The angles of observation are as follows：first，the great recession will go back to normal track after a period of adjustment；second，the economic power of the U.S.is still much more stronger than others；third，American people has aversion to war；fourth，America is absorbing lessons from the decline of Great Britain. However，from the view point of the rule of social development，the American system has some fundamental weaknesses.The greediness of Wall Street and the dominant desire of Washington D.C.has created a lot of contradictions domestically and globally，which can not be overcome by American political system itself. Nowadays，in a world of fierce competition，only those countries who can make her economic growth sustainable not only good in creating wealth but in distribution as well are invincible.