One embodiment of the present invention relates to a method whereby a terminal transmits data to another terminal in a wireless communication system, the data transmission method comprising the steps of: selecting resources for transmitting multiple pieces of data; and transmitting the multiple pieces of data by using the selected resources, wherein the terminal is configured to execute the transmission through sensing, and if the terminal fails to transmit the data a preset number of times or more in a row, the terminal reselects resources.