When performing a read operation on a non-volatile memory device which includes a plurality of memory sections each corresponding to a plurality of data units, the read count of a specific memory section and the error bits of its corresponding data units are monitored for determining whether data relocation should be perform. When the read count of the specific section exceeds a read count threshold and the error bits of any corresponding data unit exceeds an error threshold, data is moved from the specific memory section to another memory section of the non-volatile memory device, thereby preventing read disturbance from occurring in the specific memory sections.