A radio base station (T-eNB) is configured to set up a data forwarding tunnel for forwarding user plane data to the radio base station (T-eNB) only for an access bearer for which the user plane data to be forwarded exists, when receiving a notification from a handover-source radio base station (S-eNB) as to whether or not the user plane data to be forwarded exists for each access bearer. The notification being made by using a handover request message for the mobile station (UE), and the access bearer being set up between the radio base station (T-eNB) and a upper level node (SGW).