This study aims to add to the scientific treasures in the field of Islamic law, especially maslahah mursalah in determining Islamic law according to the thoughts of Najmuddin At-Thufi and Asy Syatibi. The type of research used is library research with descriptive analytical approach. This study describes the opinion of Najmuddin At-Thufi and Asy Syatibi in the problem of maslahah mursalah in determining Islamic law. While the data source consists of two aspects, namely primary data and secondary data sources. The results of the study obtained that maslahah mursalah according to Najmuddin At-Thufi and Asy Syatibi. Setting reason higher than revelation or hadith because the basis of Islamic law is the benefit of humans, while the benefit itself can be achieved through reason. However, in this case At-Thufi and Asy Syatibi limit their use, in the use of maslahah it only applies in the field of mu'amalah and customs while in worship it has become a provision of Allah SWT. Because according to him, if there is a conflict between the text and maslahah, then what is prioritized in that context is maslahah. However, in the process of prioritizing maslahah over texts, the mechanism that must be followed is by means of takhsis and tabyin, not by erasing or abandoning the rules contained in the texts. Najmuddin At-Thufi and Asy Syatibi's view on maslahah is to set reason higher than revelation or hadith because the basis of Islamic law is benefit, while benefit itself can be achieved through reason.