The present invention discloses a UE (User Equipment) and a method of the UE for receiving downlink data to avoid the occurrence of mistakes when the UE receives the downlink data. The method comprises the following steps: during the reestablishment, in the process of transmitting Service Data Units (SDU) to a Packet Data Convergence Protocol (PDCP) layer entity from a Radio Link Control (RLC) layer entity in the UE, if the PDCP entity judges that the PDCP Sequence Number (SN) of the received PDCP Protocol Data Unit (PDU) which includes the SDU satisfies the report condition, the PDCP PDU is received and the SDU included in the PDCP PDU is submitted to the upper layer entity, wherein the report condition is: PDCP SN=(Last_Submitted_PDCP_RX_SN+1)%(Maximum_PDCP_SN+1).