Provided are an apparatus and method for transmitting a packet. The apparatus and method indicate a policy with respect to an acknowledgement packet and a retransmission packet, which correspond to the type of data to be transmitted, in a packet included in the data. The apparatus includes a Media Access Control (MAC) control unit which determines the type of packet to be transmitted, and sets the packet to indicate an acknowledgement policy and a retransmission policy with respect to the packet; and a communication unit which transmits the packet.