Abstract: Collaborative work system requires specific users being able to assign some other system users to specific roles under the control of system.We developed an authorization supported role-based access control model named ASRBAC to satisfy this requirement.In order to realize this model in real world,this paper discusses some important problems which are critical to model the realization using object-oriented methodology,including consistency problem,dynamic monitor,constraint management and security control. This model can be applied in large-scale systems,especially large collaborative work system. Integrated with authentication technology,it can protect information security in large systems.