To enable optical isomers to be resolved by adsorptive separation with increased efficiency of absorptive separation and adsorption selectivity by using a specific adsorbent and an optically active compound-containing desorption agent.

(A) An absorbent containing zeolite of ≥3wt.% benzene adsorption capacity and (B) an optically active compound-containing desorption agent are used to effect the adsorption separation of (C) optical isomers, preferably an optically active amine, an optically active carboxylic acid or its derivative. The zeolite in the component A preferably has 10 or more oxygen atoms on the pore opening ring and in the case that the zeolite is crystalline aluminosilicate, the molar ratio of silica/alumina is preferably ≥2. In addition, the zeolite to be used is preferably faujasite type zeolite, β-type zeolite and a pentasil type zeolite. In the component B, the concentration of the optically active compound is preferably ≥1%, more preferably ≥10%.