According to an embodiment of the present disclosure, a method for transmitting, by a user equipment (UE), uplink data in a wireless communication system supporting a narrowband Internet of things (NB-IoT) system includes: receiving information related to a preconfigured uplink (UL) resource (PUR) for transmitting the uplink data in an RRC connected state; and transmitting the uplink data by using the preconfigured uplink resource (PUR) in an RRC idle state. In the transmitting of the uplink data, when the preconfigured UL resource (PUR) is a dedicated resource and there is no data to be transmitted in the preconfigured UL resource (PUR), transmission of the uplink data is skipped.