In this paper, a Role-based Access Control (RBAC) model is applied and extended to a multimedia version called Multi-Role Based Access Control (MRBAC), which can fully support the comprehensive and multilevel security control requirements of the distributed multimedia applications. The object-oriented concept is adopted in MRBAC to perform the hybrid role hierarchy management and security roles and rules administration. In summary, MRBAC can: 1) support the multi-level security protection for multimedia data; 2) provide access control by checking both the time constrains and IP addresses; and 3) decentralize the administration functions to make the access control management more efficient.