For direct HPLC resolution of enantiomers of optically active substances, supports having an optically pure organic layer with a high order of chirality are advantageous. To ensure this, the support itself has to possess a structure of well-defined regularity. For this reason, zeolite A, a material of crystalline character has been used as support, for the preparation of “brush type” chiral stationary phases instead of the conventional amorphous macroporous silica support. The aim of the present work is to certify the crystalline properties of the zeolite A during the modification. The application of the CSPs for the resolution of DL-serine is presented.