A memory system includes a memory device including multiple memory blocks and a controller that groups the multiple memory blocks into a plurality of super blocks according to a specific condition, each of the super blocks including two or more memory blocks, sorts a mixed super block among the super blocks, the mixed super block including a source block and a general block, the source block being a memory block having a read count equal to or greater than a reference value, the general block being a memory block having a read count smaller than the reference value, collects and regroups two or more source blocks, included in two or more mixed super blocks, into one or more source super blocks according to the specific condition, and moves valid data of the one or more source super blocks to one or more general super blocks each including general blocks only.