Method and device of judging compressed data and data storage device including the same

PURPOSE: A method and an apparatus for discriminating compression data and a data storing device including the same are provided to discriminate compression of data without information which is supplied from the outside. CONSTITUTION: A controlling unit(2300) determines the compression of data stored in storing medium without additional information. The controlling unit selectively compresses data in the storing medium according to a determination result. The controlling unit determines compression of the inputted data based on distribution of symbols. The controlling unit stores data in the storing medium.