Disclosed are a method and an apparatus for transmitting or receiving feedback information in a communication system. An operation method of a terminal comprises the steps of: receiving, from a base station, DCI #1 including scheduling information of PDSCH #1 and transmission resource information of HARQ response #1 with respect to PDSCH #1; receiving, from the base station, DCI #2 including scheduling information of PDSCH #2 and transmission resource information of HARQ response #2 with respect to PDSCH #2; and when the transmission resource information of HARQ response #1 is configured as undefined, transmitting, to the base station, HARQ response #1 and HARQ response #2 by using a resource indicated by the transmission resource information of HARQ response #2. Therefore, the performance of the communication system can be improved.