The method of separation of optical isomers in accordance with the present invention is directed to providing a method of separation of optical isomers which enables efficient optical resolution of optical isomer mixture not using expensive silica gel but using a filler which is inexpensive per se and has excellent optical resolution ability, and characterized in that particles of polysaccharide derivatives, preferably ester derivatives and carbamate derivatives of polysaccharide are used as an optical resolution filler.