An optical recording medium, a data recording or reproducing apparatus, and a data recording or reproducing method used by the data recording or reproducing apparatus. In a method of recording data on an optical disc, each of a plurality of error correction code (ECC) blocks is divided into a plurality of partitions. Next, data from the partitions is interleaved so that each of the ECC blocks is alternately and equally selected to generate a recording block. The generated recording block is modulated and recorded on an optical disc. As a result, the optical recording medium, the data recording apparatus, and the data recording method used by the apparatus are compatible with the format of a conventional digital versatile disc (DVD) and have higher error correction rates. In a reproducing method, the recording block is deinterleaved.