The present invention discloses a method for address management, at least one backup group exists between a broadband remote access server (BRAS) and a backup device, and the method includes: when the BRAS receives an access request of a user, detecting whether there is an idle address in a backup group accessed by the user; if there is no idle address in the backup group accessed by the user, then the BRAS assigning a new logical segment to the backup group, wherein the logical segment contains at least one address; and the BRAS selecting an address from the new logical segment and assigning the address to the user. The present invention also discloses an apparatus and system for address management. The method, apparatus and system of the present invention realize the flexible management of the sharing address pool, and solve the problem of a waste of resources.