Abstract: A rolecontext-based delegation model (RCBDM) is developed through studying the role-based delegation model (RDM) and extending the role-based access control model (RBAC). This model introduces rolecontext and delegation rules as the criterion for delegation. Rolecontext components including such attributes as delegation maximum and the domain, type and revocation type of delegation and relevant rules are defined to support the flexible and multi-step delegation, thus enabling system security management to control macroscopically the system at a higher level. Moreover, a delegation application example is given, by which the RCBDM is proved effective and useful.