Disclosed is a method for performing a synchronization by a device-to-device (D2D) terminal in a wireless communication system supporting D2D communication. More particularly, a method for performing a synchronization by a D2D terminal comprises the steps of: receiving a synchronization reference signal from a first synchronization source and performing a synchronization; and, if the quality of the synchronization reference signal does not meet a predetermined standard, changing the synchronization source into a second synchronization source.