Abstract:N-(diphenylphosphino)-1,1-diphenyl-N-(3-(triethoxysilyl)propyl)phosphinamine(3) was prepared by substitution reaction of γ-aminopropyl triethoxysilane(1) with chlorodiphenyl phosphine(2). A novel P-N organometallic flame retardant(5) was synthesized by the reaction of 3 with nickel chloride hexahydrate(4). The structures were characterized by 1H NMR, 31P NMR and FT-IR. Effects of molar ratio[r=n(2) : n(1)], solvent, reaction time and reaction temperature on the yield of 3 were investigated. The optimum reaction conditions were as followed: dichloromethane was solvent, 1 was 19 mmol, r was 2.3, reacted at 25 ℃ for 14 h. The yield of 3 was 89.5% under the optimum conditions. TGA results showed that the initial decomposition temperature of 5 was 252 ℃ and the char yield was about 31.9% at 700 ℃.