Cyclodextrins (CyDs) are cyclic oligosaccharides comprising six, seven, or eight glucopyranose units (called α, β, or γ, respectively) with a central cavity of the corresponding size. It is well-established that CyDs form inclusion complexes with a variety of molecular species (guests) in an aqueous medium. In complexation, both the size (and shape) and hydrophobicity of a guest molecule play important roles. In analytical chemistry, CyDs have been used as modifiers in the solvent xtraction or carriers which selectively transport certain isomers. We recently found that β-CyD is easily precipitated from aqueous solution upon introducing a cyclohexane vapor into the solution. There is a possibility that, when hydrophobic solutes are present in the aqueous solution, these solutes could be coprecipitated with CyD.