A method of determining a slot format in a wireless communication system, where the method is performed by a user equipment (UE) and includes: receiving, from a network, slot format information informing a first slot format for a plurality of normal symbols that are arranged within a period of time, wherein each of the plurality of normal symbols includes a normal cyclic prefix (CP). The method further includes: based on the received slot format information informing the first slot format, determining a second slot format for a plurality of extended symbols that are arranged within the period of time, wherein each of the plurality of extended symbols includes an extended CP.