The National Education System, as a reference for implementing education in Indonesia, has a role as a minimum standardization of educational institutions that are currently developing in Indonesia. National Education System is a basic reference for the education system that has developed in various societies, related to curriculum, educational models, institutional standards, output standards and teacher standards. National Education System is important because without national standards, education in Indonesia will experience extraordinary inequality between urban areas and rural areas or disadvantaged areas. National Education System must be understood as a generally accepted minimum standard. Related to that, the government through the National Accreditation Board tries to control the quality of outputs and performance of educational institutions in various regions by using minimum standards that can be applied in the regions. Every educational institution needs a useful assessment to evaluate the performance of an educational institution. In general, the assessment aims to find out the deficiencies that exist in order to be repaired or developed in the future. This article seeks to discuss the role of the National Accreditation Board in improving the quality of education in Indonesia.