A data storage device may include a first memory apparatus including a plurality of data blocks having data classified in units of data blocks; a second memory apparatus in communication with the first memory apparatus to store data cached from the first memory apparatus; and a controller in communication with the first memory apparatus and the second memory apparatus. The controller is configured to perform a caching group based caching operation by controlling the first memory apparatus to cache data from the first memory apparatus to the second memory apparatus on a caching group basis. Each caching group includes a first data block requested for caching and one or more other data blocks having the same write count as a write count of the first data block.