PROBLEM TO BE SOLVED: To provide an allergic constitution-improving agent having excellent allergic constitution-improving action, safe, and easy in the ingestion thereof.SOLUTION: The allergic constitution-improving agent comprises a sulfation product of a neutral polysaccharide or a salt thereof as an active ingredient. And an IgE production inhibitor comprising a sulfation product of a neutral polysaccharide or a salt thereof as an active ingredient is provided.COPYRIGHT: (C)2009,JPO&INPIT【課題】優れたアレルギー体質改善作用を有し、且つ安全で摂取しやすい、アレルギー体質改善剤の提供。【解決手段】中性多糖類の硫酸化物又はその塩を有効成分とするアレルギー体質改善剤。【選択図】なし