The correlation of photographic performance of indocarbocyanine dyes having different substituent groups on the benzene ring and the heterocyclic nitrogen atom with their electrochemical properties and aggregation behavior in solution and on emulsion grains was investigated. The experimental results indicate that the physicochemical properties of the dyes are determined by their skeletons and subtle structure features. The photographic performance of the dyed emulsion depends on the dye's photophysical and electrochemical properties and on the energy level positions of the sensitizer.