Due to the increasing amount of data available online, the World Wide Web has becoming one of the most valuable resources for information retrievals and knowledge discoveries. The Semantic Web is well recognized as an effective infrastructure to enhance visibility of knowledge on the Web. The core of the Semantic Web is ontology, which is used to explicitly represent our conceptualizations. The Authorization control has become an important field of research for many software systems. It is related to database security which is concerned with preventing any unauthorized user to have access on any confidential information. Access control is an essential operation in standard information systems to prevent unauthorized access and use of information from the system. Due to various data sensitivities various authorization and access control mechanisms are needed in the area of data base security. Semantics of data should be considered in order to specify effective authorization control techniques. In this paper we review the various methodologies for authorization control of a semantic data repository.