During his visit to Yan 'an on 1945, Huang Yanpei talked with Mao Zedong in a cave (the conversation between Mao Zedong and Huang Yanpei was called "the couple in the cave"), saying, "I was born more than 60 years ago, but what I saw with my own eyes is really called" its prosperity is ambiguous "and" its death is ambiguous ". One person, one family, one. This is probably the first time to raise the question of the cycle rate of dynasty rise and fall. More than a dozen dynasties in history enjoyed a long time, a larger territory and stronger national strength. I have listed a detailed table here (see the following table 1). Although some dynasties were short-lived, they were important and ranked. As can be seen from this table, some dynasties lasted longer, such as the Western Han Dynasty, the Eastern Han Dynasty, the Northern Song Dynasty and the Southern Song Dynasty, which lasted for nearly 200 years or even longer, and the Tang, Ming and Qing Dynasties lasted for nearly 300 years.

These dynasties all had a similar course, that is, prosperity-stagnation-decline, and were replaced by new dynasties. The problems faced by different dynasties are similar. To borrow Huang Yanpei's words, it is called the cycle rate of dynasty rise and fall. Those short-lived dynasties, such as the Qin Dynasty and the Sui Dynasty, experienced rapid prosperity and rapid demise, and their contradictions quickly intensified and broke out in a very short time, which seems to explain more clearly the role of the rise and fall cycle rate of dynasties.