A method for triggering an aperiodic sounding reference symbol, includes: receiving a Downlink Control Information (DCI) indicating a transmission of an aperiodic Sounding Reference Symbol (SRS) from a base station which configures a resource used for transmission of the aperiodic SRS; maintaining the resource for transmitting the aperiodic SRS when there is at least one of a loss of uplink synchronization when a timer relating to the uplink synchronization expires and a failure in transmission of a scheduling request transmitted more than a predetermined number of times; and executing a random access procedure.