Eyewitness testimony is one of the most important evidences in criminal law. The purpose of this article is to investigate the comparative attitude to witness testimony in jurisprudence, Iranian criminal law and the International Criminal Court. Based on this, the question of the article can be raised as follows: What is the attitude towards the testimony of witnesses in Iranian jurisprudence, criminal law and the International Criminal Court? This article is descriptive and analytical and the mentioned question has been investigated using the library method. The findings indicate that the testimony of witnesses is of great importance in Iranian jurisprudence and criminal law and it is considered one of the important reasons for proving a crime, so that witnesses may be summoned to testify. In the International Criminal Court, the testimony of witnesses is also important, but the testimony of witnesses is voluntary and there is no compulsion in this regard. The most important effects of the type of attitude towards witness testimony are manifested in witness support. In Iran's criminal law, various mechanisms have been considered, such as non-disclosure of witness information, hearing testimony through remote means and executive protection measures. These actions in the International Criminal Court are different in some cases, such as non-disclosure of witness statements and in some other cases, such as the adoption of executive measures, although the International Court has limited possibilities in the field of adopting executive measures to protect witnesses.