This specification provides a method of performing a bandwidth part (BWP) operation in a wireless communication system. Specifically, The method performed by a terminal includes receiving a first message including information related to at least one initial BWP configuration from a network, receiving a second message including configuration information for an additional BWP from the network, receiving downlink control information (DCI) related to BWP switching for at least one configured BWP from the network, and transmitting and receiving signals to and from the network in an activated BWP based on the received DCI.