A memory system includes a memory device including dies, each of the dies including planes, each of the planes including blocks, each of the blocks including pages; and a controller suitable for controlling the memory device, the controller comprising: a memory including a mapping table which includes map chunks generated through dividing map data into map chunks each of a unit size; a pattern determination engine suitable for determining patterns with respect to each of the map chunks received from the memory; and a compression engine suitable for determining whether to perform compression on the map chunks, based on pattern determination results for the map chunks determined by the pattern determination engine, and performing compression on those map chunks for which performing compression was determined.