Abstract: To the complexity control problems in a complex information systems which was usually caused by the mana-gement of large numbers roles and the dynamically changing of the user’s responsibilities attributes,in this paper,we based on the full consideration of the relationship between the user’s authorization and the form of the use’s organization,used the organization and group as the main body to assigned the roles,and increasing the resource access permissions scope defined in information system,we proposed an improved RBAC model and designed the realized data relationships．Practical results show that not only can be easily complete the authorization which caused by the responsibilities changing of the organization and groups,and can quickly respond to the change of the property caused by the personnel duty,at the same time can flexibly achieve the resource access permissions.

Key words: Role-based access control,Access control,Authority management,Resource management,User group