A memory system includes a memory device including a plurality of memory blocks, each memory block including a plurality of word lines, each word line being coupled to a plurality of memory cells, and a controller suitable for grouping the word lines into a plurality of word line groups, wherein when receiving a read command for data stored in a first memory block, the controller performs a read operation for word lines of the first memory block, checks for read fail word lines in the word lines of the first memory block, checks for word line groups including the read fail word lines, and transmits a set command corresponding to the read fail word lines to the word line groups which contain read fail word lines.