A method and an apparatus for configuring transmission time interval (TTI), including a processor configured to execute instructions to: transmit to a user equipment (UE) configuration information about data radio bearers (DRBs), the configuration information about DRBs indicating TTI length to which each DRB configured by the eNB for the UE is applicable, wherein the DRBs are configured by radio resource control (RRC), and notify a target eNB of the TTI length to which each DRB of the UE is applicable when the UE needs to be handed over.