A Closed Subscriber Group (CSG) information processing method, an access control method, and the corresponding system and devices are disclosed herein. The CSG information processing method includes: obtaining modified CSG information of User Equipment (UE); and sending a message that carries the CSG information to the UE. The method and the corresponding system and devices enable the UE to know the change of the stored CSG information. The access control method includes: obtaining modified CSG information; and detaching a UE from an accessed CSG area when discovering that the UE is not allowed to access the accessed CSG area any longer according to the modified CSG information. The access control method and the corresponding system and devices implement access control under a CSG mechanism.