Qin unified China and the currency, and stipulated that gold was the superior currency, with the unit of "one" (20 taels); Copper is the next coin, and the unit is "half two". During the Warring States Period and the Qin Dynasty, there were half a tael of money. At first, it was the national currency, and later it was changed to the square hole round currency. After the reunification of the Qin dynasty, the whole country carried out half a penny. Since then, the currency form of square hole round notes has been used for more than two thousand years.

"Historical Records, Pingzhun Biography" quoted "Notes of Ancient and Modern Times": "Qin Qian is half a Liang, with a diameter of one inch and two cents, and weighs twelve baht." Today, Qin Banliang's money varies in size, with a diameter of 3.2-3.4 cm and a weight of about 8 grams. Qian Wen is long and narrow, slightly curved. No inner and outer Guo, flat back. Some of them weigh more than 10 g, or even more than 20 g, which is still the "when white" contained in Suoyin.

The Significance of Unified Currency in Qin Dynasty

1. Political unification: The unification of currency in Qin Dynasty was an important reform measure after Qin Shihuang unified six countries. Under the influence of the unified currency, the use of the same currency in different places eliminated the confusion of currencies in different countries and regions, which was conducive to strengthening the central government's control and unified management of the whole country and further consolidating the political unity of the Qin Dynasty.

2. Economic development: Qin unified the currency, which promoted the prosperity of trade and economy. On the basis of currency unification, commodity exchange has become more convenient, commercial activities have been promoted and the economy has developed accordingly. A unified currency is also conducive to stimulating people's enthusiasm and creativity in production and promoting the prosperity of agriculture, handicrafts and commerce.

3. Cultural inheritance: The unified currency in the Qin Dynasty also contributed to cultural inheritance and exchange. By unifying the currency, people in different regions can communicate more conveniently and promote cultural integration and exchange. The unified currency also laid the foundation for the unification of characters and laws in the Qin Dynasty, which is of great significance for the inheritance and development of national culture.