Provided are a method and apparatus for transmitting data in a wireless communication system. The method comprises the steps of: setting up a frame including both a control domain for transmitting scheduling information to a first terminal and a data domain for transmitting first data to the first terminal; and transmitting, to a second terminal, second data in the control domain. The frame comprises a plurality of orthogonal frequency division multiplexing (OFDM) symbols in a time domain. The control domain consists of a first number N (where N is any natural number equal to or less than 4) of OFDM symbols in the frame. The data domain consists of OFDM symbols other than a number N of OFDM symbols in the frame. The second data has a predetermined bit size.