System and method of selecting source and destination blocks for wear-leveling

An operating method of a memory system comprising a plurality of memory blocks, the operating method comprising:

• selecting source and target memory blocks based on an erase count list storing current erase count (EC) information of the memory blocks;
• and
• performing a wear-leveling operation between the source and target memory blocks selected from the memory blocks,
• wherein the selecting of the source and target memory blocks includes:
• selecting one having the greatest EC as the source memory block from the erase count list, and
• selecting of the target memory block is performed by selecting the target memory block from remaining ones among the memory blocks other than both of the source memory block and an immediately previous target memory block of an immediately previous wear-leveling operation, and
• wherein the selecting of the target memory block identifies the immediately previous target memory block of the immediately previous wear-leveling operation through a swap list including swap information of the memory blocks and information on the source and target memory blocks.