Copper coins in the Western Han Dynasty were still named by weight, but the weight gradually did not match the name. There are three main types of copper coins in the Western Han Dynasty: half two, three and five baht. At the end of the Western Han Dynasty, during the Regency and the New Dynasty, Wang Mang carried out four major monetary reforms in more than ten years, all of which ended in failure. All the money minted in the Eastern Han Dynasty was five baht.
During the period of social unrest in the Three Kingdoms, Wei, Jin, Southern and Northern Dynasties, the circulation scope of metal money was reduced, and the value of money was different, which led to the phenomenon of valuing money over money. During the Three Kingdoms period, Cao Wei implemented the monetary policy in kind, and Wei Mingdi resumed casting five baht, which was similar to the Eastern Han Dynasty. Shu Han and Wu Dong spend most of their time making big money. The main currencies are: 150 baht, 100 baht, etc. Wu coins mainly include: Daquan 500 and Daquan.
After the establishment of the Western Jin Dynasty, the old coins of the Han and Wei Dynasties were mainly used, as well as grain, silk and other physical objects. Wu's old money was used at the beginning of the Eastern Jin Dynasty, and then five baht small money appeared.
During the Southern and Northern Dynasties, the society was very turbulent, the currency value was chaotic, and the phenomenon of private casting was serious. Since the Northern Wei Dynasty, Qian Wen gradually got rid of the restriction of discipline and gradually made a transition to the annual money system.
The establishment of Sui Dynasty made China's chaotic currency tend to be unified. In the third year, Emperor Wendi minted a standard five-baht coin and prohibited the circulation of old coins. Kaiyuan Bao Tong, the annual currency minted by Tang Wude in the fourth year of Kaiyuan Bao Tong, is gone forever, and replaced by Bowen's monetary system (mainly Bao Tong, Yuanbao and Chongbao). Kaiyuan Bao Tong was the main casting in the Tang Dynasty for 300 years.
Five Dynasties and Ten Countries, political division, regime change, like a merry-go-round. In order to weaken the strength of other countries, countries enhance their own strength by casting bad coins, so there are many coins, but the quality is not high.
The coinage industry in Song Dynasty was relatively developed, surpassing the previous generation in quantity and quality, which was another peak after Wang Mang's money. Copper coins dominated the Song Dynasty and iron coins dominated the Southern Song Dynasty. After the Northern Song Dynasty, the annual money really began to prevail, and almost every time the annual number was changed, new money was cast. At the same time, the circulation of silver has also achieved an important position. During the Northern Song Dynasty, Jiaozi, the earliest paper money in the world, appeared.