There is provided di-substituted iminoheterocyclic compounds of the following formula (I): in which, A is optionally substituted alkyl group, optionally substituted aryl group or optionally substituted heterocyclic group; X is oxygen atom, sulfur atom, carbon atom or nitrogen atom; the group —X—Y— represents optionally substituted alkylene or cyclic alkenylene bond; and B1 and B2 are, hydrogen atom, optionally substituted alkyl group, optionally substituted aryl group or optionally substituted heterocyclic group, independent from each other, or a pharmaceutically acceptable salt thereof. These compounds have good affinity for α4β2 nicotinic acetylcholine receptors and activate the same to thereby exert a preventive or therapeutic effect on cerebral dysfunction.