A method and apparatus for deciding a secondary eNB (SeNB) user equipment aggregate maximum bit rate (UE-AMBR) in a wireless communication system is provided. In one embodiment, a master evolved NodeB (MeNB) in dual connectivity receives assistant information, which includes at least one of a buffer size or load information of a SeNB, from the SeNB, and decides whether to change a SeNB UE-AMBR based on the assistant information. In another embodiment, the MeNB transmits an indication which requests change of a SeNB UE-AMBR to a SeNB, receives information related to a new SeNB UE-AMBR from the SeNB; and decides whether to change the SeNB UE-AMBR based on the information related to the new SeNB UE-AMBR.