From the Warring States Period to the Three Kingdom Period （475 B.C.-280 A.D.）China experienced the establishment, consolidation and development of the feudal, absolute monarchy. During the period traditional Chinese medicine developed quickly, and it transformed from empirical practice to a systematic theoretical and clinical system, which had a profound influence on its development in the later two thousand years.

The Warring States Period （475-221 B.C.） lasted for about 250 years, and all the states established their own independent regimes. The Qin State became rapidly stronger and stronger after political reform, and in 221 A.D. it unified the whole nation and ended the separatist rule, thus, establishing the first centralized feudal autocratic dynasty in the Chinese history. Afterwards, the peasant uprising led by Chen Sheng and Wu Guang overthrew the Qin Dynasty （221-207 B.C.）, which was replaced by the Han Dynasty （206 B.C.-220 A.D.）.