According to one embodiment, a memory controller controlling a NAND memory having D bits/cell, includes: a code encoder which generates a code word having correction capability of t symbols; a write control unit which controls writing of the code word to the NAND memory; and a code decoder which decodes the code word read from the NAND memory, wherein the write control unit dispersedly allocates 2×D pages stored in adjacent two word lines in a block of the NAND memory to 2×D/t or more code words.