Photophysical characterization of perimidine 1, 1-methylperimidine 2, 2-phenylperimidine 3, 1-methyl-2-phenylperimidine 4, 2-(2'-hydroxyphenyl)perimidine 5, 1-methyl-2-(2'-hydroxyphenyl)perimidine 6, 2-(2'-methoxyphenyl)perimidine 7 and 1-methyl-2(2'-methoxyphenyl)perimidine 8 has been achieved. All derivatives exhibit a high photostability against the UV light with small photochemical quantum yields phi(r) in the range of 10(-5)-10(-6), implying that non-radiative processes different from the excited state intramolecular proton transfer (ESIPT) mechanism are responsible for their photophysics.