Abstract In the present study, 2-naphthylamine substituted cyclotetraphosphazenes were synthesized and characterized for the first time. The reaction of octachlorocyclotetraphosphazene (1) with 2-naphthylamine (2) was performed in a THF solution and gave eight products (3-10). All the 2-naphthylamine substituted cyclotetraphosphazene compounds (3-10) were fully characterized by elemental analysis, MALDI-TOF mass spectrometry, 1H, 13C and 31P NMR spectroscopies. The molecular structure of the non-geminal bis-substituted 2- naphthylamine cyclotetraphosphazene compound 3 (2-trans-6) was also determined by X-ray crystallography. Compounds 3, 4 and 8 could be formed by an SN2 mechanism. Compounds 5-7, 9 and 10 might be formed by both SN1 and SN2 reaction mechanisms. These mechanisms were supported by 31P NMR and X-ray crystallography results.