There are provided a memory system and an operating method thereof. A method for operating a memory system includes: performing a program operation on a first page of a first page group included in a first memory block and storing physical-logical address mapping information on the first page in a physical-logical address mapping information storing section; performing a program operation on a second page of the first page group included in the first memory block and storing physical-logical address mapping information on the second page in the physical-logical address mapping information storing section; and copying the physical-logical address mapping information on the first and second pages of the first page group, which are stored in the physical-logical address mapping information storing section, to a second memory block.