Abstract: Polystyrene-divinylbenzenc (4%) copolymer beads is combined with anhydrous aluminium chloride and titanium tetrachloride ( 1:1) in CS₂ to form a complex containing11.4% of chlorine,in which the ratio of the metal aluminum to the metal titanium approach to 2 :1 (Al/Ti=2/1) It correspond to (6.42×10^-4mol A1C1₃ + 3.21×10^-4mol TiCl₄)/ 1 g complex beads.The complex is a strong solid Lewis acid and is very stable in air.The polystyrene-AlCl₃/TiCl₄ complex (PS-Al/Ti) can be uscd to catalyze a lot of organic synthesis reactions in high yield,such as esterifications,acetal formations,kclal formations,ethcrications and the Friedel-Crafts alkylations.The fact that dibasic metal complex (PS-Al/Ti) is more reactive than the polystyrene-AiCl₃ complex and the polystyrenc-TiCl₄ complex is confirmed in many reactions.It is important that the complex (PS-Al/Ti) as a catalyst can be used repeatedly at least 7 times with high yield.