The surface pressure-area isotherms of the monolayers of three kinds of amphiphilic derivatives of 8-hydroxyquinoline, N-hexadecyl-8-hydroxy-2-quinolinecarboxamide (1), 2-hexadecyloxycarbonyl-8-hydroxyquinoline (2) and 8-hexadecyloxy-2-quinaldinic acid (3) at an air-water interface on subphases with and without metal ion were investigated and compared with each other. Some information regarding the packing density and phase transition under different experimental conditions has been obtained. At the air-water interface1, 2and3can form metal complexes with Cu2+ion present in the aqueous phase. The formation of complexes leads to changes in the area per molecule and the collapse pressure of the monolayer. X-ray photoelectron spectroscopy analysis reveals Cu-ligand ratios in the LB films to beca.1:1 for1and2and 1:2 for3. Low-angle X-ray diffraction measurements showed the LB films of1, 2and3deposited from CuCl2subsolution had good homogeneity and were Y-type bilayer films.