Abstract: Spatial database systems and location-based services share a common access control requirement,i.e.,the same user will be assigned different access rights when this user moves into different spatial extent.The access permissions assigned to users are based on their present locations.The novel access control model is badly needed to cope with this scenario that the user's access rights are mutable.An access control model with spatial characteristics named as Spatial-RBAC is proposed.We study the main components of the model,such as spatial area constraints,separation of duties spatial constraint and spatial cardinality constraint of role activation.These constraints can control the assignment of roles,the change of role state,the assignment of privileges,the activation of roles and etc,which strengthen the security capability.In the model applications,we have developed some location judging algorithms to identify effectively the change of the user locations and improve the practicability of Spatial-RBAC.