The adsorbability of alpha-naphthol orange (NO) onto the dicationic Langmuir-Blodgett (LB) films of N,N’-omega-p-xylene-bis-[stearyldimethylammonium chloride] (XSAC) with octadecane was investigated. As a result, the specific adsorbability of mixed LB films was observed for NO molecules at the molar fraction of 0.25, The film structures before and after dye adsorption were also studied by using Fourier transform infrared spectroscopy, UV-Vis spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. It was found that NO molecules have the same molecular arrangements in both NO-adsorbed LB films and XSAC-NO-complexed LB films.