An NK1 receptor antagonist composition of the present invention uses maltooligosaccharide having an NK1 receptor antagonistic activity as an active ingredient. A suitable amount of the maltooligosaccharide to be blended in the NK1 receptor antagonist composition of the present invention is 0.000001 to 70% by weight. The NK1 receptor antagonist composition of the present invention is prepared for use into various forms of external agents, internal medicines, foods and beverages by blending various materials as the ingredients other than the active ingredient. The NK1 receptor antagonist composition of the present invention has high safety for being used for pharmaceuticals and has satisfactory therapeutic effects.