This article attempts to explain the definition of quality assurance in higher education,and after describing the concept of quality assurance we will present various methods of quality assurance in higher education.
The paper proceeds by analysis of accreditation as a relatively complete method in quality assurance and we will consider the historical development of accreditation in higher education. Also, different approaches to accreditation and different types of it are studied here. As a concluding remark accreditation comparative study in higher education system of different countries are assessed to find an appropriate model for accreditation.