Abstract: A method for transmitting an uplink pilot signal in a wireless communication system is disclosed. The method for transmitting an uplink pilot signal in a wireless communication system includes forming a basic unit including a plurality of pilot Resource Elements (REs) and data REs and having a size of 4 subcarriers×9 Orthogonal Frequency Division Multiple Access (OFDMA) symbols, setting the plurality of pilot REs in the basic unit, and transmitting the basic unit to a base station. Each of the REs is time-frequency resource defined by one symbol index and one subcarrier index.