An upper node and a handover source radio base station store setup
information on an access bearer having been set up between the upper node
and the handover source radio base station. A mobile communication method
according to the present invention includes the steps of: (A) informing,
from the handover source radio base station to a handover target radio
base station, the access bearer setup information; (B) storing, at the
handover target radio base station, the access bearer setup information
informed of by the handover target radio base station; and (C) setting
up, at the upper node, an access bearer between the upper node and the
handover target radio base station by using the stored access bearer
setup information without performing reallocation processing of new
access bearer setup information, the access bearer being set up in
response to a path switching request from the handover target radio base
station.