There is provided a mobile radio communication system which is capable of reducing a group ID in length with respect to the number of mobile stations and realizing efficiency of air resources. Suspend control of mobile stations is performed by notifying not only control information but also transmission/reception state update information for instructing a state [Active/Suspend] in a status update frame set in advance from a base station to the mobile stations using an HS-SCCH. The base station performs the suspend control by sending, in state update information at timing of a state update frame number of a user ID allocated in advance, a group ID of a user ID allocated to mobile stations desired to be made Active in advance.