The present invention relates to compounds of 3-aryl-3-methyl-quinoline-2,4-diones acting as a 5HT6 receptor antagonist, a preparation method thereof, and a pharmaceutical composition containing the same for treatment of the central nervous system disorders. The compounds of 3-aryl-3-methyl-quinoline-2,4-diones according to the present invention may be valuably used for treatment of a 5HT6 receptor relating disorders because of its excellent binding affinity for the 5HT6 receptor and excellent selectivity for the 5HT6 receptor over other receptors.