A packing material for liquid chromatography, which comprises an optically active compound having the formula: ##STR1## wherein Ar is a phenyl group, an .alpha.-naphthyl group or a .beta.-naphthyl group, R.sub.1 is an alkyl group having from 1 to 4 carbon atoms, a phenyl group or a 3,5-dinitrophenyl group, R.sub.2 is an alkyl group having from 1 to 4 carbon atoms, *indicates an asymmetric carbon atom and n is an integer of 2 or 3, as a stationary phase.