The present invention relates to a method and apparatus for feeding back acknowledgement/negative-ACK (ACK/NACK) by a receiving device in a wireless communication system. Specifically, the method comprises the steps of: receiving data from a transmitting device; and feeding back ACK/NACK for data to the transmitting device, wherein the size of resource for ACK/NACK is determined on the basis of a distance between the transmitting device and the receiving device. The receiving device is capable of communicating with at least one of another transmitting device, a transmitting device related to an autonomous driving vehicle, a base station or a network.