"Tang Lu Yishu" was originally named Lu Shu; Also known as Tang law, Tang law is sparse, so Tang law is sparse, which is one of the earliest written laws in East Asia. The Law of the Tang Dynasty and its annotations are also the oldest and most complete feudal criminal code in China, with a total of 30 volumes.

Yonghui Law Book is not only a code of Tang Dynasty, but also a book on the history of Chinese legal system, including the early Tang Dynasty. Some of these contents have reached a complete level after long-term development. Reading Yong Hui Law can help us to understand not only the contents of the legal system in the Tang Dynasty, but also some contents of the legal history of China, including the early Tang Dynasty, and gain knowledge of the theoretical basis for the establishment of important systems in China. As a masterpiece of feudal law, the Law of the Tang Dynasty is regarded as the representative of the Chinese legal system, one of the five legal systems in the world, and has a far-reaching influence in the legal history of China and Southeast Asia. The perfection of the Tang Law marks the maturity of China's legal system. A regional legal system is constructed with the Tang law of feudal China as its connotation and the laws of neighboring feudal countries as its extension. The Chinese legal system and the other four legal systems in the world are also called the five legal systems in the world. Legal system refers to the classification of laws according to historical traditions. All laws with the same historical tradition constitute the same legal system. Chinese legal system refers to the ancient legal system in China, which is one of the five legal systems in the world and occupies an important position in the world legal history. China's legal system is similar to other legal systems, but it also has its own inherent characteristics. With his unique style, he influenced all the places in Asia where he had contacts and occupied an important position in the history of world legal system. In the legal history of China, the law of the Tang Dynasty plays an important role in connecting the past with the future. No matter the legislative ideas, principles, text style or legal content, they all inherited the achievements of the previous generation of legislation, and at the same time developed and innovated, which made the Tang law integrate the characteristics of the feudal code, develop and improve itself and become a complete feudal legal form. The law of the Tang Dynasty not only greatly promoted the politics and economy of the Tang Dynasty, but also directly influenced the development of China's feudal legal system, and became a model for later feudal legislation. People in the Yuan Dynasty said in the Preface to the Law of Yonghui: "Multiply it (referring to the law of the Tang Dynasty) to make it pass, and divide it into times. If you pass and fail, you have nothing. " In other words, the revision of the Tang law, arbitrary multiplication, division, addition and deletion, is either too much or too little, which will affect its integrity and rigor. It is precisely because of its rigorous structure, concise words, accurate annotations and complete contents that the Law of the Tang Dynasty was regarded as a model for amending laws and regulations by later generations, and it was not abolished. The legislation of the five dynasties countries was basically taken from the Tang Dynasty. 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. As a powerful feudal empire, the Tang Dynasty was once the political, economic and cultural center of Asia. Its advanced culture (including law) was spread in all directions by foreign businessmen, monks and students coming and going from Chang 'an. It was the Tang Law that had a great influence on ancient Southeast Asian countries and became the source of feudal legislation in Southeast Asian countries. 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.