Provided are a method and a device for performing a UE-based handover in a next generation wireless access network. The method of a UE may include receiving, from a source base station, an upper layer signaling including information on UE-based handover command and information on conditions for handover execution; storing a target cell configuration by using the information on conditions for handover execution; and determining whether to perform a handover procedure to a target cell, by determining whether predetermined conditions for handover are satisfied.