An uplink control information (UCI) transmitting method and device in a wireless communication system are provided. The method receives a first ACK/NACK resource indicator (ARI) in a first downlink bandwidth part (BWP), receives a second ARI in a second downlink BWP, determines UCI transmitted in an uplink BWP according to whether a first physical uplink control channel (PUCCH) resource indicated by the first ARI is the same as a second PUCCH resource indicated by the second ARI, and transmits the determined UCI through the uplink BWP.