Methods and apparatuses for releasing preconfigured uplink resources configuration in a wireless communication system are disclosed herein. In one method, a User Equipment (UE) receives a configuration of a preconfigured uplink resource (PUR) when the UE is in a first RRC_CONNECTED state. The UE enters a first RRC_IDLE state from the first RRC_CONNECTED state. The UE performs a first transmission using the PUR when the UE is in the first RRC_IDLE state. The UE enters a second RRC_CONNECTED state from the first RRC_IDLE state. The UE suspends the configuration when the UE is in the second RRC_CONNECTED state. The UE resumes the configuration when the UE enters a second RRC_IDLE state from the second RRC_CONNECTED state. The UE performs a second transmission using the PUR when the UE is in the second RRC_IDLE state.