The J-aggregates of quinocyanine dyes (5,6,5'6'-dibenzo-1,1'-diethyl-2,2'-cyanine chloride (Sh) and 1-methyl-1'-octadecyl-2,2'-cyanine perchlorate (S120)) have been fabricated in a Langmuir trough and transferred onto quartz substrate. The formation of the J-aggregates has been studied by methods of conventional absorption and fluorescence time resolved spectroscopy. The mixed J-aggregate of S120 and Sh shows two distinct absorption bands and one fluorescence band intermediate between those of the J-aggregates of the individual component dyes. These results have some anomaly compared with the mixed J-aggregates of quinocyanine dyes and its benzothiazole or benzoselenazole derivative formed in solutions (Scheibe et al., Naturwissenschaften 29 474 (1937)) and in Langmuir-Blodgett films (Penner and Mobius, Thin Solid Films 132 185 (1985)).