A successful marriage of Web and RBAC technology can support effective enterprise-wide security in large-scale systems. But RBAC has a role hierarchy concept that senior role inherits all permissions of junior roles. In the corporate environments, senior role need not have all authority of junior roles, and unconditional inheritance in role hierarchy causes undesirable side effects(permission abuse) and violates the principle of least privilege. In this paper¹, we re-explore role and permission inheritance and propose a new model providing restricted permission inheritance. To do this, we divide a single role into sub-roles(Corporate/Department Common role, Restricted Inheritance role, Private Role) based on the degree of inheritance and business characteristics and make role hierarchy with sub-roles. It is very useful to solve unconditional inheritance problem in a corporate environment. And we describe formal description of proposed model. Lastly, we show a system architecture applying RBAC with proposed model within a corporate web environment.