A method for determining a user equipment, UE, specific search space for Long Term Evolution wireless communication systems, comprising: determining, by a UE, the number of downlink control information, DCI, bits of each type of control channel currently required to be monitored by the UE; determining, by the UE, a temporary UE specific search space corresponding to each type of control channel currently required to be monitored by the UE, according to a mapping relationship between a component carrier for carrying a data channel and a component carrier for carrying a control channel, wherein the mapping relationship is currently used by the UE; and for control channels that are currently required to be monitored by the UE and are of a same control channel element, CCE, aggregation level, when there exist one or more types of control channels, other than a selected type of control channel in the control channels, that have the same number of DCI bits as the selected type of control channel, determining, by the UE, that an actual UE specific search space corresponding to the selected type of control channel is formed by all CCEs of a union of temporary UE specific search spaces corresponding to all of the types of control channels having the same number of the DCI bits as the selected type of control channel; wherein the determining, by the UE, a temporary UE specific search space corresponding to each type of control channel currently required to be monitored by the UE comprises: determining a temporary UE specific search space corresponding to each component carrier for carrying a data channel; and determining the temporary UE specific search space corresponding to each type of control channel currently required to be monitored by the UE, according to a control channel corresponding to the component carrier for carrying a data channel and the temporary UE specific search space corresponding to the component carrier for carrying a data channel. determining, by a UE, the number of downlink control information, DCI, bits of each type of control channel currently required to be monitored by the UE; determining, by the UE, a temporary UE specific search space corresponding to each type of control channel currently required to be monitored by the UE, according to a mapping relationship between a component carrier for carrying a data channel and a component carrier for carrying a control channel, wherein the mapping relationship is currently used by the UE; and for control channels that are currently required to be monitored by the UE and are of a same control channel element, CCE, aggregation level, when there exist one or more types of control channels, other than a selected type of control channel in the control channels, that have the same number of DCI bits as the selected type of control channel, determining, by the UE, that an actual UE specific search space corresponding to the selected type of control channel is formed by all CCEs of a union of temporary UE specific search spaces corresponding to all of the types of control channels having the same number of the DCI bits as the selected type of control channel; wherein the determining, by the UE, a temporary UE specific search space corresponding to each type of control channel currently required to be monitored by the UE comprises: determining a temporary UE specific search space corresponding to each component carrier for carrying a data channel; and determining the temporary UE specific search space corresponding to each type of control channel currently required to be monitored by the UE, according to a control channel corresponding to the component carrier for carrying a data channel and the temporary UE specific search space corresponding to the component carrier for carrying a data channel. determining a temporary UE specific search space corresponding to each component carrier for carrying a data channel; and determining the temporary UE specific search space corresponding to each type of control channel currently required to be monitored by the UE, according to a control channel corresponding to the component carrier for carrying a data channel and the temporary UE specific search space corresponding to the component carrier for carrying a data channel.