The present invention relates to a method for power control by a first terminal that performs device-to-device (D2D) communication in a wireless communication system. More specifically, the method comprises the steps of: receiving, from a base station, a first signal including power control information defined for D2D communication; and transmitting a second signal according to transmission power determined on the basis of the received first signal, wherein the power control information indicates one of broadcast and groupcast, and the second signal is differently masked and transmitted according to a transmission method of the second signal.