A method for communicating downlink control information, comprising: mapping, by a base station according to an order of indexes of orthogonal frequency division multiplexing, OFDM, symbols used by an enhanced physical downlink control channel, E-PDCCH, of a user equipment, UE, the E-PDCCH sequentially to resource elements used to transmit the E-PDCCH in each OFDM symbol; and sending, by the base station, the E-PDCCH to the UE by using the resource elements; wherein the E-PDCCH and a physical downlink shared channel, PDSCH, invoked by the E-PDCCH are frequency-division multiplexed; wherein the step of mapping the E-PDCCH sequentially to resource elements used to transmit the E-PDCCH in each OFDM symbol comprises: mapping, by the base station according to an order of subcarriers in each OFDM symbol, the E-PDCCH sequentially to resource elements used to transmit the E-PDCCH and occupied by L control channel elements allocated to the E-PDCCH, wherein L is an integer; wherein the step of mapping the E-PDCCH sequentially to resource elements used to transmit the E-PDCCH and occupied by L control channel elements allocated to the E-PDCCH comprises: mapping modulation symbols of the E-PDCCH with index numbers of j 0 + [0,..., N -1] sequentially to resource elements of a set R, wherein j 0 is a start position of the modulation symbols of the E-PDCCH mapped in the OFDM symbol; the set R is a set of resource elements used to transmit the E-PDCCH and occupied by the L control channel elements allocated to the E-PDCCH in the OFDM symbol; N is the quantity of the resource elements in the set R; and N and j 0 are integers. mapping, by a base station according to an order of indexes of orthogonal frequency division multiplexing, OFDM, symbols used by an enhanced physical downlink control channel, E-PDCCH, of a user equipment, UE, the E-PDCCH sequentially to resource elements used to transmit the E-PDCCH in each OFDM symbol; and sending, by the base station, the E-PDCCH to the UE by using the resource elements; wherein the E-PDCCH and a physical downlink shared channel, PDSCH, invoked by the E-PDCCH are frequency-division multiplexed; wherein the step of mapping the E-PDCCH sequentially to resource elements used to transmit the E-PDCCH in each OFDM symbol comprises: mapping, by the base station according to an order of subcarriers in each OFDM symbol, the E-PDCCH sequentially to resource elements used to transmit the E-PDCCH and occupied by L control channel elements allocated to the E-PDCCH, wherein L is an integer; mapping, by the base station according to an order of subcarriers in each OFDM symbol, the E-PDCCH sequentially to resource elements used to transmit the E-PDCCH and occupied by L control channel elements allocated to the E-PDCCH, wherein L is an integer; wherein the step of mapping the E-PDCCH sequentially to resource elements used to transmit the E-PDCCH and occupied by L control channel elements allocated to the E-PDCCH comprises: mapping modulation symbols of the E-PDCCH with index numbers of j 0 + [0,..., N -1] sequentially to resource elements of a set R, wherein j 0 is a start position of the modulation symbols of the E-PDCCH mapped in the OFDM symbol; the set R is a set of resource elements used to transmit the E-PDCCH and occupied by the L control channel elements allocated to the E-PDCCH in the OFDM symbol; N is the quantity of the resource elements in the set R; and N and j 0 are integers. mapping modulation symbols of the E-PDCCH with index numbers of j 0 + [0,..., N -1] sequentially to resource elements of a set R, wherein j 0 is a start position of the modulation symbols of the E-PDCCH mapped in the OFDM symbol; the set R is a set of resource elements used to transmit the E-PDCCH and occupied by the L control channel elements allocated to the E-PDCCH in the OFDM symbol; N is the quantity of the resource elements in the set R; and N and j 0 are integers.