A method and a user equipment (UE) for transmitting an aperiodic sounding reference signal (SRS) in a wireless communication system are discussed. The method according to an embodiment includes receiving an aperiodic SRS power offset parameter for the aperiodic SRS from a base station (BS) through a radio resource control (RRC) signaling; receiving common parameters for SRSs, including the aperiodic SRS, from the BS through the RRC signaling; setting a transmission power of the aperiodic SRS based on the aperiodic SRS power offset parameter and the common parameters; and transmitting the aperiodic SRS to the BS based on the transmission power of the aperiodic SRS. The aperiodic SRS power offset parameter is a non-common parameter used for transmitting the aperiodic SRS but not a periodic SRS which is included in the SRSs.