Base Station (BS) and User Equipment (UE) apparatuses for configuring a Random Access CHannel (RACH), and methods thereof, are provided. The method for a BS to configure a RACH includes generating configuration information on RACH resources, transmitting the configuration information on the RACH resources to a UE, receiving a random access preamble multiplexed on a plurality of continuous RACH resources from the UE, extracting the random access preamble multiplexed on the plurality of continuous RACH resources, and detecting the extracted random access preamble. The method for a UE to configure a RACH includes receiving configuration information on RACH resources from a BS, selecting occupied RACH resources among a plurality of continuous RACH resources, generating a random access preamble, multiplexing the generated random access preamble on the selected RACH resources, and transmitting the random access preamble on the selected RACH resources to the BS.