An apparatus for transmitting data in a communication system includes: a receiving unit configured to receive reception information of a data packet in a receiver from the receiver; a frame generation unit configured to generate a plurality of frames containing data to transmit to the receiver, in consideration of the reception information; a packet generation unit configured to include the plurality of frames into a payload and generate a data packet; and a transmitting unit configured to transmit the generated data packet to the receiver, wherein the payload includes a mode field containing information on the plurality of frames and the plurality of frames.