The requirements of "Kaiyuan Tongbao" money casting are already very strict, and the sample money must be made and submitted to the emperor for examination and approval. In the pre-Qin period, Qian Wen used the ancient prose of six countries, namely Da Zhuan; From the Qin Dynasty to the end of Sui Dynasty, Xiao Zhuan was used, while Kaiyuan Qian used Ou Yangxun's eight-part script, that is, official script. It shows that the money system in the Tang Dynasty entered a new era in the monetary history of China. The decorative decoration on the back of Kaiyuan coins is a deliberate depiction of coins, which adds to the aesthetics and practicality of coins. The shape and characteristics of Kaiyuan money were not only inherited by later dynasties, but also had a far-reaching impact on the casting of money in neighboring countries such as North Korea, Japan and Annan (Vietnam).
In the fourth year of Wude (AD 621), Tang Gaozu created the money balance law of bronze treasures, abolished all old money and cast "Kaiyuan Tongbao". Since then, China's ancient square-hole round coins were no longer named after weight, but were dubbed as "Tongbao", "Yuanbao" and "Chongbao". The "two currencies of baht" that have been circulating for more than 8 years have since completed its historical mission and really withdrawn from the circulation field. The appearance of "Kaiyuan" treasure money in the Tang Dynasty lasted until the end of the Qing Dynasty, which became a new milestone in the history of ancient Chinese currency.