A method and apparatus for priority handling between a prioritized MAC CE and a SR for data in a wireless communication system is provided. A wireless device determines a prioritized Media Access Control (MAC) Control Element (MAC CE) which is prioritized over a data in Logical Channel Prioritization. The wireless device triggers Scheduling Request (SR) for requesting resource for the data. Based on that Physical Uplink Control Channel (PUCCH) transmission of the triggered SR is overlapped with uplink transmission of a first MAC PDU including the prioritized MAC CE, the wireless device (1) prioritizes the uplink transmission of the first MAC PDU over the PUCCH transmission of the triggered SR transmission, and (2) performs the uplink transmission of the first MAC PDU.