Abstract: This paper proposes two methods for wear leveling of FAT file system in NAND Flash memory, by keeping the corresponding item in FAT table for deleted file and writing data to new cluster when rewriting a file.These methods have achieved wear leveling efficiently and extended the life of NAND Flash memory at the expense of read and write speed.The research of wear leveling in file system level has less difficulty and compatible with FAT filel system, so it has feasibility and practical.