A method used in an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) (350) for synchronizing PDCP operations after a RRC connection re-establishment procedure with a user equipment (UE) (310) is provided. The method includes: initiating an RRC reconfiguration procedure to resume all radio bearers other than a signaling radio bearer 1 (SRB1) when an RRC connection is re-established; and re-transmitting a designated group of PDCP Service Data Units (SDUs) to the UE (310) when a data radio bearer (DRB) mapped on Radio Link Control (RLC) Acknowledged Mode (AM) is resumed.