A memory system may include: one or more normal memory regions; one or more spare memory regions; and a controller suitable for controlling the normal memory regions and the spare memory regions. The controller may determine, among the normal memory regions, a first normal cell region that includes a concentrated cell region whose access count exceeds a first threshold and neighboring cell regions in a set range from the concentrated cell region perform first address mapping to map an address of the first normal cell region to an address of a first spare cell region in the spare memory regions, and perform second address mapping to map the address of the first spare cell region to an address of a second normal cell region in the normal memory regions, when an access count of the first spare cell region exceeds a second threshold.