The novel kind of alkoxysilyl-containing aromatic imine terminator, N-benzylidene-3-(triethoxysilyl)-1-propanea mine(TEOS) was synthesized firstly, and then end functionalized polystyrene（PS-TEOS）was prepared via anionic in-situ polymerization by the reaction of poly(styryl)lithium with TEOS. The terminator and functionalized PS were characterized by FT-IR, ¹H-NMR and GPC. The quantitative reaction relationship between TEOS and poly(styryl) lithium, and the influence of the TEOS content, reaction temperature, reaction time, number-average relative molecular mass of poly(styryl) lithium on the functionality were investigated. The results show that TEOS can react with poly(styryl)lithium stoichiometrically and the terminating reaction was completed in 10 min～15 min, terminating temperature at 55 ℃～80 ℃ and Mn of poly(styryl) lithium at 5000～50000 have no significant effect on the functionality of PS. The functionalized PS with high functionality (>80% ) was prepared with TEOS as terminator.