Method for transmitting uplink control information in wireless communication system, and device therefor

A terminal configured to support at least one cell having one or more transmission time interval (TTI) lengths in a wireless communication system, the terminal comprising:

• a transmitted and a receiver;
• and
• a processor that controls the transmitter and the receiver,
• wherein the processor:
• receives downlink (DL) control information,
• determines whether to transmit channel state information together with an acknowledgement/negative acknowledgement (ACK/NACK) for a DL data channel scheduled by the DL control information, based on whether an index of a modulation and coding scheme (MCS) field of the received DL control information is lower than an index of an MCS field of previously received DL control information, and
• transmits the channel state information together with the ACK/NACK based on the determination that the index of the MCS field of the received DL control information is lower than the index of the MCS field of the previously received DL control information.