The optical resolution of DL-pantolactone is effected by reacting DL-pantolactone or its alkali salt derived therefrom, respectively, with an optically active N-substituted aminophenylpropanol of the general formula: ##STR1## wherein R.sub.1 is a phenyl group which may be substituted and R.sub.2 is an aralkyl group in which the benzene ring may bear a substituent, or its mineral acid addition salt; separating the resulting diastereomers by the aid of difference in their dissolubility; and decomposing them to give the corresponding optical antipodes. This method can provide the antipodes in high purity and yield and can be carried out with ease.