Flash memory system and word line interleaving method thereof

Provided are a flash memory system and a word line interleaving method thereof. The flash memory system includes a memory cell array, and a word line interleaving logic. The memory cell array is connected to a plurality of word lines. The word line (WL) interleaving logic performs an interleaving operation on WL data corresponding to at least two different wordlines and programming data, including the interleaved data, to the memory cell array.