offered is an anticonvulsive composition which comprises an effective amount of a dihydrouracil derivative represented by the formula : ## str1 ## , a naphthyl group or a diphenylmethyl group , and the other is a hydrogen atom , a lower alkyl group , a lower alkenyl group , a cyclopentyl group , a cyclohexyl group or ## str3 ## , r 1 , r 2 and r 3 are hydrogen atoms or lower alkyl groups , and x is an oxygen atom or a sulfur atom ] and at least one pharmaceutically acceptable carrier .