Disclosed are a method for transmitting/receiving uplink control information between a terminal and a base station and a device supporting same in a licensed assisted access (LAA) system in which the base station or the terminal executes listen-before-talk (LBT)-based signal transmission. Specifically, disclosed are: a method for a terminal efficiently transmitting uplink control information to a base station when the terminal transmits the uplink control information to a transmission time interval (TTI) that is shorter than the length of one subframe; and a device supporting same.