There is provided a novel architecture for transmitting multimedia data with different QoSs in a mobile communication system. In a protocol structure according to the present invention, an RLP layer receives data with different QoSs and dividing the data into datagrams according to the QoSs, a MUX layer multiplexes the datagrams received from the RLP layer and outputs multiplexed TU data, and a QCCH receives the multiplexed TU data and outputs TU blocks with the QoSs by puncturing and repeating information added according to the QoSs for the multiplexed TU data.