A transmission method for carrier aggregation, more particularly, for uplink MIMO and carrier aggregation, in a method for transmitting an uplink signal by the carrier aggregation in a terminal having at least four antennas, includes receiving a grant signal for transmission of the uplink signal, the grant signal including information related to use of a primary cell and a secondary cell, determining one antenna or at least two antennas to use the primary cell, determining one antenna or at least two antennas to use the secondary cell, and transmitting a first uplink signal to the primary cell and a second uplink signal to the secondary cell using the respective determined antennas.