Tang Dynasty was founded by Li Yuan on 6 18. After the establishment of the Tang Dynasty, the government soon promulgated the monetary policy. In the autumn of Wude four years, the court ordered the abolition of five baht and the casting and issuance of Kaiyuan Baotong money. Kaiyuan Bao Tong is eight points in diameter and weighs two baht and four ginseng. Ten Wen Kaiyuan Bao Tong's money weighs one or two, and thousands of Wen Kaiyuan Bao Tong's money weighs six catties and four liang. "

The Tang Dynasty established the legal status of national coinage. At the same time, it inherited the tradition of taking silk as currency in Wei, Jin, Southern and Northern Dynasties, and implemented the monetary system of money and silk in parallel. The money here refers to the copper coin-Kaiyuan Bao Tong, and silk is the general name of silk products, including brocade, embroidery, silk, silk, silk, silk, silk, silk, silk, silk, silk, silk, silk, silk, silk. In fact, it is a diversified monetary system in which physical currency and metal currency circulate together.