Discussion on Tang Law is the earliest and most complete feudal code and annotation in Chinese history. On Tang Law is one of the representative works of ancient feudal codes in China, and it is also the earliest preserved code so far. It has an unusual position in ancient times and now. On the Law of the Tang Dynasty not only preserves the law of the Tang Dynasty completely, but also preserves a lot of contents, styles and forms of the law of the Tang Dynasty. At the same time, it records a great deal of information about politics, social economy in the Tang Dynasty, and is an important basis for studying the class relationship, hierarchical relationship, official system, military system, land system and tax system in the Tang Dynasty. Therefore, Wang Mingsheng, a scholar in Qing Dynasty, called The Law of Tang Dynasty a rare treasure. As a feudal code, A Brief Discussion on the Laws of the Tang Dynasty has a strong feudal consciousness and embodies the class will of the feudal ruling class. It reflects the ritual system, absolute monarchy, hierarchical system and patriarchal clan system. The legal thoughts in A Brief Discussion on the Laws of the Tang Dynasty have the following two characteristics: first, "morality is the foundation of politics and religion, and punishment is used for politics and religion", and ethics and law are combined, with the former as the main and the latter as the auxiliary. Second, simplify legal provisions and reduce punishment. For example, compared with Sui Law, 92 death sentences were removed in Zhenguan Law, and the number of people was reduced to 7 1, and many of them were lighter.

The laws of the Tang Dynasty were formulated on the basis of the Emperor's Law of the Sui Dynasty, which inherited the laws of the previous generation. According to the experience of feudal legislation and judicature since Qin and Han Dynasties, the Law of the Tang Dynasty sorted out some effective charges, criminal system and judicial principles, and made clear provisions on all major aspects of social relations. Therefore, it was a masterpiece of China's feudal laws before the Tang Dynasty, and it became the blueprint for the formulation and interpretation of feudal codes in the Song, Yuan, Ming and Qing Dynasties, which had a wide and far-reaching impact on the establishment and improvement of feudal legal systems in ancient Japan, Korea and Viet Nam. Known as one of the five legal systems in the world and the representative of Chinese legal system. As far as the law is concerned, the Criminal Code of the Song Dynasty is just a copy of the law of the Tang Dynasty. Twenty articles in Zhiyuan Xinge in Yuan Dynasty are the same as nine articles in Tang Law, and the other eight opinions, ten evils and official system all follow Tang Law. The Daming Law in the Ming Dynasty and the Qing Law in the Qing Dynasty were both influenced by the laws of the Tang Dynasty.

In the first year of Dabao (76 1), Emperor Wenwu of Japan enacted the Dabao Law, with 6 volumes and 12 articles. The title and order of the articles are the same as those of the Tang Dynasty, and the contents of the laws are similar. Korea's Koryo law is not only the same as the Tang law in content system, but also very similar to the Tang law in terms of the types of criminal names and preferential terms of the privileged class. In Vietnam, the criminal laws of the past dynasties were also modeled after the laws of the Tang Dynasty.