A method of supporting a buffer status report associated with a device-to-device (D2D) communication includes: establishing an RRC connection with an eNB; receiving, by a UE, configuration information associated with a D2D communication from the eNB, the configuration information including information of a resource selection mode for a D2D data transmission, the information of a resource selection mode indicating a resource pool from which the UE selects a resource for a D2D data transmission to another UE; identifying a D2D target identity of at least one target UE to which the UE transmits D2D data by performing a D2D discovery procedure; setting an RRC message to be transmitted to the eNB, the RRC message including information of the identified D2D target identity; and transmitting the RRC message to the eNB, the information of the identified D2D target identity being transmitted through UEinformation message for a D2D data transmission.