History can be divided into various segments based on the various .developing stages. We call these segments eras. The era issue has been raised to discuss time and time again, which is often associated with the major transition of political system, economic system and ideology in world life, and sometimes also linked with a number of far-reaching historical events. In the recent 15-20 years, we have many important issues that prompt people to rethink of the era issues, like the East and West economic restructuring, the collapse of the former Soviet Union, the war in Iraq and the former Yugoslavia, the "9 -11" event and the war in Afghanistan and Iraq, as well as all aspects of major global changes resulting from the process of globalization. It should be pointed out that in the West's political, academic and business circle, there are very few articles totally devoted to the clef'tuition of era; most of people only mention the word "era" or such kind of expression here and there in their political speeches or writings.