An apparatus implements methods for random access in a wireless communication system using beamforming. A Subscriber Station (SS) measures a best downlink transmission beam among downlink transmission beams transmitted from a Base Station (BS), and transmits Random Access Channel (RACH) information, which includes indication information indicating the best downlink transmission beam, to the BS. The BS receives RACH information which includes indication information indicating a best downlink transmission beam among downlink transmission beams, and detects an RACH sequence and the best downlink transmission beam from the received RACH information.