A context-aware role-based access control system and a control method thereof. The context-aware role-based access control system includes: a context-aware user assignment manager (CAUAM) for performing a role assignment function, a role delegation function, or a role revocation function for a user according to a context of the user, based on a preset context request condition; a context-aware permission assignment manager (CAPAM) for performing a permission modification, a permission restoration, and a personalized permission modification for a permission, which the role has, according to changes in the context of the user; an information repository for storing a user profile and context information; and an access control manager (ACM) for controlling the context-aware user assignment manager, the context-aware permission assignment manager, and the information repository, and processing an access control request. Accordingly, more efficient access control can be achieved in ubiquitous environments where the context of the user dynamically changes.