The present invention relates to the field of wireless communications technologies and discloses a method, an apparatus, and a system for setting up a Radio Bearer (RB) in order to enable end-to-end RB setup from a User Equipment (UE) to an evolved NodeB (eNB) in a relay network system. The method includes: receiving a first RB setup message sent by an eNB; performing RB setup preprocessing according to the first RB setup message; generating a second RB setup message according to a result of the RB setup preprocessing; and sending the second RB setup message to a UE, notifying the UE to set up an RB on an access link. The present invention is mainly applicable to the relay network system.