The present invention provides an aminopropylidene derivative represented by the formula (I), having excellent histamine receptor antagonistic action, a compound which is useful as a pharmaceutical composition, especially as an active ingredient such as an antihistamine, having alleviated side effects in the central nervous system, such as drowsiness. In the formula, R 1 and R 2 , which may be identical or different, stand for a hydrogen, a substituted carbonyl, a substituted carbonylalkyl, and acrylic acid with proviso that a case where both are hydrogen is excluded； R 3 and R 4 , which may be identical or different, stand for hydrogen, an alkyl which may be substituted with phenyl, or the like； A stands for unsubstituted or an oxo； B stands for a carbon or an oxygen； one of X and Y stands for a carbon and the other stands for a sulfur, a broken line part stands for a single bond or a double bond, and a wavy line stands for cis-form and/or trans-form.
