Provided are a apparatus and method for transmitting data and a apparatus and method for receiving data, in which a transmitting station sets priorities among a plurality of data to be transmitted and a receiving station processes the plurality of data according to the priorities. The apparatus for transmitting data includes a packet-generation module which generates a plurality of data and a packet that includes the plurality of data and that specifies priorities between the plurality of data; and a communication module which transmits the packet through a communication channel.