As a supporter of individual and social rights, the judiciary has obligations to protect people's rights, which is within the legal jurisdiction of this branch. Part of the judiciary's obligations in this regard are carried out through the prosecutor. The public prosecutor is a judicial official who officially accuses people of committing a crime and prosecutes them in court. The purpose of this article is to examine the question of what duties and obligations does the prosecutor have in the legal system of Iran and the United States of America in the pursuit of public rights? The present article is theoretical and by using the descriptive-analytical method and in a library form, it has explained the tasks and actions of the prosecutor in the preservation of public rights and citizen's rights. The findings indicate that according to the Constitution of the Judiciary, and accordingly, the prosecutor and the related cyber authorities in this branch should guarantee public rights and deal with the factors that violate these rights in line with their duties. In fact, the feeling of justice and trust in the judicial system is provided to the people as a result of the judicial supervision of the provision and fulfillment of the rights of the citizens. In American law, the prosecutor has important duties in front of public law and civil rights, which must perform these duties fairly and impartially and seek to guarantee justice and the rights of individuals.