A series of polymethylene-bis-β-naphthoates and bis-β-naphthyl alkanes and their derivatives have been synthesized.and their flnorescenve spectra have been studied.Intramoleoular ezcimer formations have been observed.in all oases.In the case of polymethylene-bis-,B-naphthoates,the egoimex flnoresoenoe intensities are xelated to methylene chain lengths.The fluorescence intensity of the on.with trimethylene chain is the strongest.In the case of snbstitnted bis-β-naphthyl alkanes,by introducing electron-attracting groups in the side chain,the electron densities of the two naphthalene rings become unequal.The λ_max valves of the fluorescence emissions of the intramoleoular egoimers are blue shifted.in comparison with the unsnbstituted 1,3-bis-β-naphthyl propane.The λ_max valves of the exeimers remain unaltered,but the I_E/I₂ valves deoxease with the increase of solvent polarity.So that,their properties shown do not completely resemble that of the typical exeimers nor that of the typical egoipleges.