Abstract: A flame retardant polyphenylene ether resin composition excellent in heat aging resistance and impact resistance is disclosed. The composition comprises(A) a polyphenylene ether resin,(B) an aromatic alkenyl resin,(C) a modified polyorganosiloxane having an average particle diameter of 0.08 to 0.6 .mu.m,(D) a phosphate, and(E) a particulate silicic acid.