The point of departure for the law and the sign of the adherence to the rule of law is the existence of a constitution in one country. In the legal system of Iran, the safeguarding of the constitution is enforced by the Guardian Council and the judiciary. Nevertheless, the Guardian Council seems to be in line with the principles of fair trial enshrined in the constitution, When reviewing the legal and fundamental principles of the Code of Criminal Procedure, approved in 1392, some of the provisions of this law are in conflict with the principles of fair trial enshrined in the constitution. Accordingly, the analysis of existing conflicts, as well as the possibility of invoking the judges of the courts to the constitution, as well as the non-implementation of legal provisions against the principles of the Constitution. The present study, with a descriptive-analytical method, attempts to measure the compliance with ordinary laws related to the principles of superiority and, in the event of a change and non-conformity, to describe the guarantee of the implementation of these contradictions. The results indicate that the Code of Criminal Procedure, passed in 1392, despite the great progress made in observing the principles of fair trial enshrined in the constitution, in cases related to the right to appoint a lawyer and the publicity of dealing with political and press congresses, the principles related to separation of powers And other cases, contain sentences contrary to the spirit of the Constitution.