A method is provided for transmitting Device-to-Device (D2D) data by a first user equipment (UE) in a wireless communication system. The first UE configured a subframe set for D2D communication through a Radio Resource Control (RRC) signaling. The first UE receives a Physical Downlink Control Channel (PDCCH) including first D2D scheduling information from a base station in a subframe #n, wherein n is an integer of 0 or more. The first UE transmits the D2D data to a second UE based on the first D2D scheduling information, in a first available subframe of the subframe set for D2D communication after a subframe #(n+k), where k is a positive integer.