A method for transmitting channel state information (CSI) on a transmission opportunity (TxOP) duration by a user equipment (UE) in a wireless communication system supporting a unlicensed band, includes measuring CSI of the TxOP duration based on CSI interference measurement (CSI-IM) and/or CSI reference signal (CSI-RS) in one or more time intervals via the unlicensed band, wherein the one or more time intervals are determined based on a starting point of the TxOP duration; and transmitting the CSI to a base station.