Provided is a system of performing a random access between a base station and a terminal using a plurality of carriers. When using the plurality of carriers, an uplink carrier and a downlink carrier may be mapped to each other in 1:n or 1:1. The terminal may perform the random access based on mapping information between the uplink carrier and the downlink carrier. A random access success rate increases and thus a time used for the random access may decrease. A wireless resource may also be effectively used.