An inhibitor for cognitive function decline or an improver for learning ability is provided. The inhibitor for cognitive function decline or the improver for learning ability contains, as an active ingredient, a liver hydrolysate having a lipid content less than 2 mass% or a phosphatidylcholine content less than 1 mass%.本發明提供一種認知功能低下抑制劑、學習能力提高劑。 本發明之認知功能低下抑制劑或學習能力提高劑將脂質含量未達2質量%或磷脂醯膽鹼含量未達1質量%之肝臟水解物作為有效成分。