A random access method in a beam division multiple access (BDMA) system including: receiving, by a terminal, a reference signal of at least one beam sector transmitted from an access point (AP) device; estimating, by the terminal, whether the terminal is in a center area of the beam sector provided by the AP device or in the boundary area of the beam sector by using the strength of the reference signal; transmitting, by the terminal, a different preamble to the AP device in accordance with location information of whether the terminal is located in the center area or in the boundary area; and determining, by the AP device, a target beam sector for transmitting information about uplink resources to be used by the terminal, among a plurality of beam sectors on the basis of the received preamble.