According to various embodiments, disclosed are a method by which a terminal performs sidelink communication in a wireless communication system for supporting a sidelink, and an apparatus therefor. Disclosed are a method by which a first terminal performs sidelink communication in a wireless communication system for supporting a sidelink, and an apparatus therefor, the method comprising the steps of: transmitting a discovery signal in a discovery resource region; receiving a discovery response signal; and performing sidelink communication with a second terminal, wherein the transmission power related to the sidelink communication is determined on the basis of a reference signal received power (RSRP) value measured in the discovery resource region.