This article compares and analyses the similarities and differences between the six-killing system of the Tang Dynasty and the relevant legal system of the Eastern Roman Empire. As an important part of the ancient criminal law system

the six-killing system of the Tang Dynasty embodies the detailed classification and severe punishment of murder

which plays a key role in maintaining social order and justice. The legal system of the Eastern Roman Empire

on the basis of inheriting the essence of ancient Greek and Roman law

incorporated Christian teachings and formed a unique legal system

focusing on legal impartiality and authority. Through the comparative analysis of the two in terms of the identification of crimes

punishment standards

judicial procedures and trial system

it reveals the differences and characteristics of the ancient civilisations of the East and the West in terms of legal culture. The research in this paper not only helps us to deeply understand the similarities and differences between the legal systems of the East and the West in ancient times

but also provides valuable historical reference for the improvement of the modern legal system.