This disclosure provides a data sending method and receiving method, and user equipment thereof, and relates to the field of communications technologies. The data receiving method applied to user equipment includes: determining whether a Medium Access Cntrol (MAC) Protocol Data Unit (PDU) received by the user equipment includes a reserved Logical Channel Identity (LCID) value; and when the MAC PDU includes a reserved LCID value, discarding a Service Data Unit (SDU) or sub-PDU corresponding to the reserved LCID value in the MAC PDU.