A method and system for sending and receiving data, for use in solving the problem that an RLC layer may process a data packet in a whole only when a transmission time arrives, which renders a long processing time in the entire process. In embodiments of the present invention, received PDCP PDUs are combined into RLC PDUs and are allocated with corresponding RLC SNs, wherein each RLC PDU corresponds to an RLC SN, and each RLC PDU comprises at least one PDCP PDU; data corresponding to scheduling resources is generated according to the generated RLC PDUs; the data corresponding to the scheduling resources is combined into an MAC PDU for data receiving. The solution in the embodiments of the present invention may shorten the length of time in layer-2 data packet processing.