A method and apparatus are provided for recovering data efficiently even when data loss has occurred over a channel or network. The packet transmission method includes arranging a first transmission packet in a source symbol in a first region of a source block; arranging a second transmission packet in a space starting with an empty space of a last source symbol where the first transmission packet is arranged, remaining after arranging the first transmission packet; arranging information related to the second transmission packet in a second region of the source block; performing Forward Error Correction (FEC) encoding on the source block; and transmitting the encoded source block.