1, 1-diamino-3, 3, 5, 5-tetra-(p-bromophenoxy)cyclotriphosphazene(ABPP) was prepared from hexachlorocyclotriphosphazene and used for the curing agent of a bisphenol A type epoxy resin(EPIKOTE 828). The effect of the curing agent on the dynamic viscoelastic properties and heat resistance of the cured epoxy resins were investigated and compared with those for the epoxy resins cured with 1, 1-diamino-3, 3, 5, 5-tetraphenoxycyclotriphosphazene(APP), 1, 1-diamino-3, 3, 5, 5-tetra-(2, 2, 2-trifluoroethoxy)cyclotriphosphazene(AFEP), 1, 3, 5-trichloro-1, 3, 5-tridimethylaminocyclotriphosphazene(Cl3), 1, 1-diamino-3, 3, 5, 5-tetra-(p-chlorophenoxy) cyclotriphosphazene(ACPP), aliphatic amine and aromatic amine. The epoxy resin cured by ABPP showed the highest storage modulus and glass transition temperature on the curing condition of 19$0^{circ}C$ for 2 hours. The epoxy resins cured with phosphazene derivatives showed superior flame proofing to those of aliphatic amine and aromatic amine. Particularly limit oxygen index of ABPP showed the highest 31.8~34.5. It is an effective curing agent for epoxy resins to enhance the storage modulus and resistance to heat.