Abstract: This article attempts to reflect on the political and social decline of the mid to late Qing Dynasty from a long-term perspective of the rise and fall cycle of dynasties.In the mid dynastic period of Chinese history,there were cyclical common phenomena: institutional fragmentation,inefficient administration,decadent customs,and declining national power.They can be summarized as the “middle leaf dilemma”.The middle stage dilemma is a “overall decline”,which can be analyzed from the dual center framework of “system customs” integration,and its driving mechanism is “accumulated drawbacks”.As the “middle period” of the rise and fall cycle of dynasties,it has been fixed in the history of political thought and is an important achievement of the accumulation of traditional Chinese governance.It is also an important manifestation of the historical “contemporaneity” of literati.The “middle period dilemma” is an insurmountable institutional and political illness that accompanies the dynastic system.Even with the boost of the Zhongxing(“中兴”) movement,it is difficult to truly restore the decline of political vitality.From this perspective,one can see a clue to the generation and extension of accumulated shortcomings in the history of the mid to late Qing Dynasty.The thinkers represented by Yan Fu believe that only by reconstructing “legal meaning”,breaking away from the dynastic system,and establishing a modern national political system,can we overcome the dilemma of accumulated drawbacks.