Base station and method for supporting random access in mobile communication system

Provided are a random access support method for a base station and a base station supporting random access in a mobile communication system supporting carrier aggregation, wherein the base station comprises a transceiver and a controller. The controller is configured to: control the transceiver to receive a first random access preamble on a primary cell; and control the transceiver to send a first random access response message corresponding to the first random access preamble on the primary cell; control the transceiver to receive a first physical uplink shared channel (PUSCH) on the primary cell according to first uplink authorization included in the first random access response message; and controll the transceiver to receive a second cell random access preamble from the terminal on a secondary cell, control the transceiver to send, to a terminal on the primary cell, a second random access response message corresponding to the second random access preamble, and control the transceiver, according to second