A method of transmitting a signal performed by a user equipment, UE, of a wireless communication system, the method comprising: receiving information about a plurality of beta offset values for determining a number of resource elements, REs, for uplink control information, UCI, to be transmitted on a physical uplink shared channel, PUSCH, wherein the plurality of beta offset values include first beta offset values and second beta offset values; receiving downlink control information, DCI, scheduling a first PUSCH; mapping first UCI including a first hybrid automatic repeat request-acknowledgement, HARQ-ACK, on the first PUSCH based on the plurality of beta offset values and a beta offset indicator included in the DCI, wherein the first beta offset values are used for mapping the first HARQ-ACK based on a priority of the first UCI being identical to a priority of the first PUSCH, and wherein the second beta offset values are used for mapping the first HARQ-ACK based on the priority of the first UCI being different from the priority of the first PUSCH; and transmitting the first PUSCH, wherein, for 'Nh / Nt' ratio exceeding a first alpha value configured in the UE, where 'Nt' denotes a total number of REs available for the first UCI and 'Nh' denotes a number of REs for the first HARQ-ACK and the first HARQ-ACK being a high priority HARQ-ACK and the first PUSCH being a low-priority PUSCH: the UE determines to transmit uplink shared channel, UL-SCH, data through Nt-Nh REs of the first PUSCH in case a second HARQ-ACK having a lower priority than the first HARQ-ACK is not included in the first UCI, and determines to drop the UL-SCH data in case the second HARQ-ACK is included in the first UCI. receiving information about a plurality of beta offset values for determining a number of resource elements, REs, for uplink control information, UCI, to be transmitted on a physical uplink shared channel, PUSCH, wherein the plurality of beta offset values include first beta offset values and second beta offset values; receiving downlink control information, DCI, scheduling a first PUSCH; mapping first UCI including a first hybrid automatic repeat request-acknowledgement, HARQ-ACK, on the first PUSCH based on the plurality of beta offset values and a beta offset indicator included in the DCI, wherein the first beta offset values are used for mapping the first HARQ-ACK based on a priority of the first UCI being identical to a priority of the first PUSCH, and wherein the second beta offset values are used for mapping the first HARQ-ACK based on the priority of the first UCI being different from the priority of the first PUSCH; and transmitting the first PUSCH, wherein, for 'Nh / Nt' ratio exceeding a first alpha value configured in the UE, where 'Nt' denotes a total number of REs available for the first UCI and 'Nh' denotes a number of REs for the first HARQ-ACK and the first HARQ-ACK being a high priority HARQ-ACK and the first PUSCH being a low-priority PUSCH: the UE determines to transmit uplink shared channel, UL-SCH, data through Nt-Nh REs of the first PUSCH in case a second HARQ-ACK having a lower priority than the first HARQ-ACK is not included in the first UCI, and determines to drop the UL-SCH data in case the second HARQ-ACK is included in the first UCI.