A memory system includes a nonvolatile memory device including a first memory area formed of memory blocks which store n-bit data per cell and a second memory area formed of memory blocks which store m-bit data per cell, where n and m are different integers, and a memory controller configured to control the nonvolatile memory device. The memory controller is configured to execute a read operation, and to execute a read reclaim operation in which valid data of a target memory block of the second memory area is transferred to one or more memory blocks of the first memory area, the target memory block selected during the read operation. The read reclaim operation is processed as complete when all the valid data of the target memory block is transferred to the one or more memory blocks of the first memory area.