A series of arylpentazoles were synthesized from p-aminophenol and its derivatives at -45 ℃. Their structures were characterized by MS and ¹H NMR. The effects of the number and position of the substituents on the stability of arylpentazoles were investigated. The decomposition pathway of arylpentazoles at different collision energy (10 eV, 60 eV)was infered by electrospray tandem mass spectrometry. The relationship between the arylpentazole stability and the relative intensity of the generation of N₅^- was also discussed. Results show that the stability of 3, 5-dimethyl-4-hydroxyphenylpentazole is the best and the ability to generate N₅^- from cleavage of C—N is most strong in these arylpentazoles at high collision energy (60 eV).