A method for branching data in a mobile communication terminal to perform data communication between a mobile station and a network which have media access control sublayers. In a data sending mode, each of the media access control sublayers of the mobile station and network attaches logical channel types based on traffic characteristic information and a radio bearer status to a media access control header contained in data to be sent. Then, each of the media access control sublayers branches the data to be sent, to transport channels corresponding to the attached logical channel types. In a data receiving mode, each of the media access control sublayers determines logical channels corresponding to logical channel types of a media access control header contained in received data. Then, each of the media access control sublayers branches the received data to the determined logical channels. Each of the media access control sublayers performs mapping and multiplexing/demultiplexing between logical channels and transport channels according to traffic characteristics to branch data. Therefore, it is possible to efficiently provide various multimedia and packet services.