An apparatus for accessing and transferring optical data has a memory supporting the page-mode function, an accessing device used to access an error correction block from the optical storage medium and store it into the memory to make the portion of data in the same column of the error correction block stored in a particular locality greater than the portion of data in the same row of the error correction block stored in the particular locality, and an error correction decoder used to access the data of the error correction block to perform the error correction process. The apparatus uses the feature of the DRAM, such as page-mode function, and the data arrangement of the memory to improve the access efficiency of the memory. The apparatus can thus increase the access speed of the error correction decoder and improve the accessing efficiency.