Naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. In this study, red-sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-4,5-naphthothiazolium(inner salt) with triethyl orthoacetate in the presence of triethylamine. The product was identified by using various analytical tools such as Elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, Mass spectrometer, $^{1}H-NMR$ spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 573nm. Therefore, it was concluded that naphthothiazolo carbocyanine dye can be used as red0sensitizing dye for the spectral sensitization of photographic emulsion.