A method for processing information given idle-mode signaling reduction (ISR) is disclosed. A serving gateway receives an information update request containing information of related to a current access network where a user equipment is located if the user equipment moves from another access network to the current access network which the user equipment has been registered. The serving gateway updates relating information of the current access network and keeps relating information of the another access networks unchanged if the information update request includes indication information of idle-mode signaling reduction activation.