“Sunshine” to the American Revolution, “Lightning” to the French Revolution, they look like twin sisters whose character is very different. Based on the traditional values, held by different attitudes, societies change to a different way forward, or the violent radical revolution, or gentle gradual reform. What is the value of tradition? Which role should be played in the present era? This is a question worth exploring. Revolutions of the United States and France have typical significance, they can provide useful inspiration to social and political development of modern China.