A method of transmitting, by a user equipment (UE), power measurement information related to beam reporting in a wireless communication system includes: receiving downlink control information (DCI) triggering reporting of the power measurement information; receiving a downlink reference signal for reporting of the power measurement information; and transmitting, to a base station, power measurement information determined based on the received downlink reference signal. A minimum required time for reporting of the power measurement information is (i) calculated as the sum of a first minimum required time from the last timing of the downlink reference signal to a transmission timing of the power measurement information and a second minimum required time between DCI triggering the downlink reference signal and reception of the downlink reference signal or (ii) calculated based on a pre-configured threshold value related to reporting of the power measurement information.