The Sunnah of the Messenger of God (PBUH) has been of great importance to Muslims since the beginning of Islam as a concept that can be the key to understanding history, hadith, jurisprudence, and the principles of Islamic beliefs. One of the important issues in the field of evidence for inferring rulings among Islamic scholars is the status of the Sunnah of the Prophet (PBUH) and how it interacts with the Quran, which has been the subject of different opinions over time. Shafi'i is a staunch supporter of the authority of the Sunnah, especially the Sunnah of the Ahad, and believes in the close interaction of the Quran and the Sunnah. This study, which uses a descriptive-analytical method to analyze and explain the position of the Sunnah in its interaction with the Quran from Imam Shafi'i's perspective, has reached the conclusion that in his opinion, the authority of the Sunnah, based on evidence from religious texts and rational evidence, is a fixed matter and on a par with the Quran, and constitutes an essential part of the semantic structure of the Quran.