Disclosed is a method for improving the solubility of isoquercitrin in water. Also disclosed is a readily water-soluble isoquercitrin composition which has improved solubility in water due to the method. Specifically disclosed is a method for preparing an isoquercitrin inclusion product, which comprises including isoquercitrin in γ-cyclodextrin in the proportion of 2 to 10 mol of γ-cyclodextrin to 1 mol of isoquercitrin.
