A method for measuring and reporting channel state information (CSI) in a wireless communication system and a device therefor. Specifically, a method for reporting, by a user equipment, channel state information (CSI) in a wireless communication system includes: receiving CSI reporting setting information related with CSI reporting; receiving one or more channel state information (CSI)-reference signals (CSI-RSs); performing the CSI reporting by using a measurement value estimated by at least one specific CSI-RS among the one or more CSI-RSs, in which the at least one specific CSI-RS may be determined based on gap information for configuring a measurement interval for estimating the measurement value and a performing timing of the CSI reporting.