The institution of the lawyer has its origins in the provisions of early Western civilization, especially Greek and Roman law, concerning defense and representation in the course of litigation. As early as the 4th-5th centuries B.C., during the period of Athens*** and the State, when the consuls heard cases, the defendant was allowed to enter a plea. In 594 B.C., Thoreau's reforms established jury courts with democratic overtones and stipulated in law that proceedings should be public and that both parties involved in a lawsuit could argue. In 454 B.C., the Senate of Rome*** and the State was forced to recognize the resolution of the People's Assembly to formulate a code of law, set up a code codification commissioner of 10, and sent people to Greece to study the legal system, to 451 B.C. to formulate the law of ten tables, and then supplemented with two tables in the second year, which is the Twelve Bronze Tables of the Law that is widely recited in later times. In Article 7 of the First Table of the Law of the Twelve Bronze Tables, it is stipulated that both parties to a lawsuit should plead their cases in turn in their appearances before the court. At the hearing, the plaintiff and the defendant are on an equal footing and may use public confrontation and argument. The judge, on the other hand, plays a neutral role and, by listening to the words and evidence of both parties, ultimately develops an understanding and judgment of the truth of the case. With the development of the Roman economy, a variety of litigation is increasing, while the emergence of statutory law makes the application of the law began to move in the direction of specialization, some litigants for various considerations, entrusted a relative or friend on behalf of their litigation. These people were initially called "Advocatus", originally meant to accompany the defendant to the court, in the trial to give advice to the defendant's relatives or friends. Initially, Advocatus could only give advice to the defendant in the courtroom and did not speak in front of the court, but later on, they developed to express their opinions to the court on behalf of the defendant and refute the allegations made by the other party. Gradually, Advocatus evolved into professional advocates, who were good at speech and debating skills, had skillful logical thinking, and were well versed in history and legal texts, and not only provided litigation and defense services for citizens, but also advised government officials on various legal aspects through the study of legal theories and the like. This principle of litigation representation and defense evolved into the system of lawyers in the third century BC. The Roman Emperor determined by imperial decree that the "canons" were engaged in the profession of "advising the common people on legal matters", and also formally stipulated that in litigation, they could entrust others to represent them in lawsuits. Such "canons" were lawyers who had obtained official recognition as lawyers. With the increase of lawyers, lawyers' guilds also gradually formed, and finally to the first century BC, professional lawyers formally appeared, and became a high social status in society at that time, the role of a huge occupation.