The present invention discloses a method for deactivating ISR and a mobility management unit. Wherein the above method includes: when an ISR deactivation is needed to be performed, the mobility management unit judging whether to perform the following operation by the S-GW according to reasons of the ISR deactivation: the mobility management unit sends a request message of deleting bearer to the S-GW, and carries, in the request message, an identifier which is used to instruct the S-GW to initiate the bearer deletion to the other mobility management unit associated with the ISR function activation; or the mobility management unit notifies the other mobility management unit associated with the ISR function activation to perform the ISR deactivation. The synchronization between the bearer deletion and the network element state in the ISR function deactivation scenarios can be realized by the above technical scheme.