The purpose of this thesis is to study the aspects of ancient Israeli judicial organizations by examining the criteria for selection of judges and their code of ethics in the Old Testament. There were three types of judges in ancient Israeli society; First, there were judges as representatives of the community(pater familias, judge, king, elder), second, there were judges as religious leaders(priests, levites), and third, there were judges as appointed officials(high officials and shopheṭ as professional judge). When these judges were selected, a standard draft was provided with specific informations in Ex 18 and Deu 1. According to Ex 18 Moses, the first judge in the wilderness era, must conduct legal education, and select capable persons as judges. In Ex 18 capable persons must firstly fear God, secondly must be sincere, and thirdly must hate unrighteous interests. They even delegated the duties of commanders of the army to these judges. The criteria for the selection of judges in Deu 1 were delegated to each tribe to select the recognized and knowledgeable persons, unlike the mention of legal education in Ex 18. They were first appointed as heads and among these the heads of thousands, hundreds, fifties and tens were selected, and shared the roles as judges and administrators in the court. For these appointed judges, the codes of ethics appear in Deu 1 and 16 and 2 Ch 19. Deu 1 is the code of ethics proposed by Jethro, the father-in-law of Moses, and presupposes that the judgment of the Israeli brothers and the Gentiles should be conducted equally for a fair judgment(v. 16). The code of ethics presented in Deu 1 is firstly not to look at appearance, secondly to listen to the small and the great alike, thirdly to be afraid of the face of any. By the code of ethics for the judges suggested by Moses in order to judge the people with justice (v. 18) in Deu 16, judge must not turn aside judgment, discern faces, take a bribe. According to the code of ethics presented by Jehoshaphat king of Judah in 2 Ch 19, consider firstly that judgment must be not on behalf of human beings, but on the Yahwe’s behalf, secondly let the fear of Yahweh be upon you and take care what you do, thirdly do in the fear of Yahweh with faithfulness and a perfect heart, and fourthly act with courage. Through these criteria for selection of judges and the code of ethics, the ancient Israeli community sought the practices of fair and justice.