A brominated diphenyl ethane mixture of the present invention comprises about 0 to about 2% by weight of pentabromodiphenyl ethane, about 55 to about 85% by weight of hexabromodiphenyl ethane, about 1 to about 20% by weight of heptabromodiphenyl ethane, about 1 to about 25% by weight of octabromodiphenyl ethane, about 0 to about 10% by weight of nonabromodiphenyl ethane, and about 0 to about 5% by weight of decabromodephenyl ethane. The brominated diphenyl ethane mixture can be added to thermoplastic resin as a flame retardant, can exhibit excellent compatibility with thermoplastic resins, can minimize the generation of environmental problems, and can obtain excellent impact resistance, thermal stability, weatherability and flowability as well as improved flame resistance.